I believe, it will change. Young's modulus has its origin in the nature of bonding including interatomic distances. In case of the heat treatment you have referred to that is quenching for hardening of steel it is martensitic transformation which leads to hardening. Martensitic transformation leads to trapping of carbon in the ferritic(martensitic) lattice and thus leads to larger interatomic separation as compared to diffusional transformation leading to formation of equilibrium ferrites. Therefore, there must be difference between Young's modulus of the steel in annealed condition (equilibrium ferrite) and hardened condition (martensite). By how much? I have not seen a literature answering this. This difference is indeed of consequence when modelling mechanical behaviour of a structure having annealed and hardened regions, like in case of weld joints. Unfortunately, this aspect has been neglected thus far and needs attention to improve accuracy of the computed results. In one of my experiments with the steel I work with I observed ~ 10% difference. However, it was a single experiment and I cannot publish this without having sufficient statistics. However, there is indeed a difference as suggested by the theoretical consideration as well as experimental observation, though the experimental observation needs to be reinforced with more experiments. 

Dear Purushothaman;

As far as I know, Young's Modulus (E) is not affected by any kind of heat treatment! E is also a function of atomic distances, thus, it is affected in elevated temperature. Imagine this, If you are testing your material in two condition, one in room temperature and the other in higher temperature, you should change E but if you are only conducting your FEA in room temperature, it does not matter what kind of hear treatments you have done. You should implement a constant E in your FEA while the deformation temperature is constant!

Best Regards,

Farhad Rahimi.

Thanks Dr. Farhad Rahimi, for answering and sharing your knowledge.

Only thing I want to know is while conducting assembly FE analysis a element  of steel material might be hardened to 60 HRC and other part in assembly is soft steel with out hardening what will be the condition to be considered as in Static FE analysis Input given is only Young's modulus and Poisson's ratio

Ordinary materials (steel for instance) contain defects (points, lines and walls) that produce internal stresses. Heat treatments may modify the density and arrangement of defects thus changing the magnitude of the overall internal stress. Young's modulus, that is a proportionality coefficient between applied stress and strain, may be modified by heat treatment, except in pure material.Young's modulus also depends on temperature as stressed by Farhad.

Thanks Dr.Patrick N.B. Anongba

If possible kindly add some literature showing conducting of  FE analysis considering heat treatment effects

Dear Purushothaman

As some literature and my experience have shown, the different heat treatments could probably leads to change of Young's modulus as Dr. Patrick N.B.Anongba has answered, but usually this effect is small and is not considered in FE analysis. While the different heat treatment will significantly affect the yield property of material, such as initial yield stress and subsequent yield.

From thermodynamics point of view, as the effective modulus changes during the external resources of energy, thus it should be change while you change entropy of total absorbed energy. I think before conducting numerical model, try to perform experiments and then figure out to simulate it.

I believe, it will change. Young's modulus has its origin in the nature of bonding including interatomic distances. In case of the heat treatment you have referred to that is quenching for hardening of steel it is martensitic transformation which leads to hardening. Martensitic transformation leads to trapping of carbon in the ferritic(martensitic) lattice and thus leads to larger interatomic separation as compared to diffusional transformation leading to formation of equilibrium ferrites. Therefore, there must be difference between Young's modulus of the steel in annealed condition (equilibrium ferrite) and hardened condition (martensite). By how much? I have not seen a literature answering this. This difference is indeed of consequence when modelling mechanical behaviour of a structure having annealed and hardened regions, like in case of weld joints. Unfortunately, this aspect has been neglected thus far and needs attention to improve accuracy of the computed results. In one of my experiments with the steel I work with I observed ~ 10% difference. However, it was a single experiment and I cannot publish this without having sufficient statistics. However, there is indeed a difference as suggested by the theoretical consideration as well as experimental observation, though the experimental observation needs to be reinforced with more experiments. 

The elastic modulus of different steel doesn't change much with heat treatments. It is bounded between 180 and 210 MPa. The differences are due to the alloying composition and the crystal structure .

Thus, heat treatments giving rise to changes in the crystal structure may lead to elastic moduli change. Concerning the presence of internal stresses mentioned by Dr. Anongba let us recall that , due to force balance, their integral contribution is zero. 

Anyway the internal stresses do not alter the linear correlation between stress and strain in the first  (linear) part of stress-strain curve.

The Young modulus is generally weakly influenced by point and line defects. However, as m entionned by Santosh, it might change because of phase transformations. For instance, in the annealed state, the microstructure consists of alpha ferrite and cementite while the as-quenched microstructure may be fully martensitic. Because these different phases have different elastic properties, the young modulus may change during a heat treatment.

If it is of interest to you.

Best regards

Dear Alberto mentioned a nice statement. if you may need to use LEM you may dismiss the modulus change, however, for none LEM if you may use elasto plastic or elasto visco plastic, you need to consider E change in your real model.

It should affect the Young's modulus. Heat treatment creates a drastic change in the inner structure of the material; not to mention the outer surface. If the treatment is made slowly, we can assume the effect homogeneous throughout the geometry; however, there is still an effect of that process. 

Even for the hardening case followed by water quenching or air cooling, for example, the temperature effect is seen until 10 mm below the outer surface (Karl-Erik Thelning, Steel and its Heat Treatment). This can be defined with a function (T versus depth); and the change of Young modulus with temperature (E versus T) defined with another cubic or higher order function; so maybe the two effects can be united. When you have E versus depth, you might fit it a curve and input the function in FEA software. But you need some data points in your hand to fit the curve. Hope it helps.

Dear all, now I am in confusion as per Mr. Santhosh Kumar and Dr Yanjie Liu effect is small and is not considered in FE analysis and as per Dr.Morteza Ghamgosar and Dr. Serra Topal  Young's modulus value varies with operating temperature, time temperature transformation in Heat treatment and therefore experimental data to be collected and input to be provided and as per Dr. Alberto D'Amore young's modulus will vary from 180 to 210 GPa therefore in FE analysis  mean value can be selected.

My condition is the analysis I am conducting is machine tool elements at temperature not exceeding 30 degree centigrade thermal effect after heat treatment will not be subjected

Your last paragraph is unclear: heat treatment involves hundreds of degrees Celsius and T difference is very fast (sudden cooling etc.). Do you have this process or not? Is it the ambient temperature you are talking about which does not exceed 30 C?

If you have heat treatment and then you are cooling the material to 30 C, you still have the inner hardening and effects of the heat treatment on the structure.

The mean value of Young modulus is a reasonable suggestion. Curve fitting will roughly give the same logic, only in a lengthy way.

There is a lot of guess work in these comments. As part of my PhD I investigated material properties with respect to randomness.

Plastic properties of metals, which are heavily influenced by dislocations, are significantly influenced by heat treatment. These processes change the structure, and the dislocations.

Elastic properties on the other hand are affected by the interactions between the subatomic particles. Heat treatment does not change the atoms themselves - only the arrangement.

Never confuse the two. Many do, and it causes issues like this. 

If you take a look at the list of material properties for metals, then you will see that  the plastic properties (yield and UTS) change a lot from material to material, but the Young's Modulus changes relatively little. This shows how the plastic properties can be easily influenced by heat treatment, but the elastic properties are not.

@ Dr. Serra Topal,

Hi Madam

I mean to say is heat treatment process is involved, carburising process takes place for increasing hardness and sudden quenching then tempering process my doubt is in FE analysis for machine elements I used to consider (200 GPa for soft condition with out heat treatment for EN 24 Steel )for the same En 24 steel after carburising and tempering what is the young's modulus value is it the same (200 GPa) is my doubt and I have mentioned about 30 degree centigrade which is about the operating condition, there will we no heat generated by the machine during the process once the machine is installed while running condition or idle condition the machine will not gets heated above 30 degree centigrade

for this condition kindly suggest the change in young's modulus value.

@ Dr. Clint Steele

Hello sir,

Thanks for helping me to understand that the heat treatment will change only the yield properties and change in young's modulus value is negligible

Young modulus will be changed due to change in character of different defect.

Technically, young's modulus depends upon the inter-atomic force vs displacement profile. Heat treatment, which does not change the lattice structure, actually should not affect the modulus. If there is a transformation to martensite or other phases, yes it should change. But a simple heat treatment with no phase change should not affect the elastic constants. Refer Dieter book on mechanical metallurgy, (pg.n0.108) where elastic constants are referred as structure insensitive properties, which means the defects in the lattice will not affect the properties. 

@ Dr. Hariharan Krishnaswamy,

Hello sir,

Thank you for clarifying my doubt with appropriate reference

When maximum temperature exceeded the thermal microfissuration threshold (different for each material) Young´s modulus decreased; consequently  it’s necessary to know this value before heating. To rocks, the T.M.T.  values are between 75 and 250ºC

Ok PhDr Calleja

There is no any elastic material, everything is a simplification of the continuum medium where interfacial energy (energy-free Gibbs) exists in the ITZ and alters the mechanical properties of metallic materials especially

Dear all,

I got a paper showing the relationship between yield properties, Young's modulus and  Thickness but not related to heat treatment

hope helpful to all for further discussion

Regards

https://mospace.umsystem.edu/xmlui/bitstream/handle/10355/29881/The_Modulus_of_Elasticity_of_Steel_Is_it_200_GPa.pdf?sequence=1

Dear all,

Please find enclosed attachment of above mentioned .pdf file

Regards

Thanks all. The question and responses are great.

It shoud be change. This is because the mechanical properties are affected by heat treatment. For example if the hardness increase the E increase and ductility decrease. And if the hardness materia is aneeled the the ductility and the toughness increase and E decreace. i.e.  see the effect of cold rolling on the mechanical properties.

Dear Dr. Hassan Sayed Hedia

I agree with your answer based on heat treatment process the Young's modulus changes but within 10 to 15 % variation i.e the variation of 20 to 30 GPa.

I am a bit surprised by everyones answer to the question. I admit that on a fundamental perspective, the structure of the steel will change with heat treatment and this may result in small variations of the modulus. However, in engineering it is definitely the common practice to use a modulus 200-210 GPa for all steels irrespective of the alloy and heat treatment. A quick browsing of any manual on structural engineering should confirm this.

Moreover, in the particular case of finite element analysis, it is important to know that the precision of the results, depending on analysis type, element type and mesh caracteristics, will rarely exceed +/-5% and can easily be of the order of +/-20% in the case of modal or non-linear analysis. Therefore, unless the model is expected to be very sensitive to a difference in stiffness, I would not change use a different value of Young's modulus for different alloys or heat treatment and then I would ensure that the used value has been demonstrated to be ''exact'.'

The Young's module can be channged by heat. When the heat is increase mechanical properties of the low carbon steelwill decrease. Expecially the properties dramatically decreasesa if you are go ovver 100 centigraqted celcius degree. Also some studies the heat is used as a modelling parameter. Such as; when you are modelled FGM in ANSYS, the material properties was accepted as a funfction of heat. and it can be changed with temperature.   

WE learn in the very basic materials science (Consult Callister) that there is relationship between structure properties and processing. As such processing (in this case heat treatment) would affect properties and sometimes structure

Regards

Dear Prabhakar,

From a physical point of view, the Young modulus of a metal is linked to the second derivative of the atomic potential energy curve, so by the stiffness of the atomic bonding. Each atom or couple of atoms have its own stiffness. Then if you add to a steel solid solution atoms (for instance W) with a higher stiffer bonds, you will increase the Young modulus of your steel.

In addition, the presence of different phases (with different Young modulus) will change the modulus of your material and in a first approximation you may evaluate this change by the rule of relative ammounts. Higher content of a stiff (high modulus) phase you have, higher will be the modulus of the material.

With this two ideas, you may consider that when doing a thermal treatment you are changing the ammounts of solid solution atoms (which will precipitate), as well as the ammount of precipitated phases. Consequently, depending on the involved atoms and phases the final result of your material (steel or other) will undergo a change of the Young modulus.

There is another last factor that you have to consider. Dislocations contribute to an easy deformation of the material and so they can start moving at low stresses and giving you a lower slope on the stress-strain curve. Be careful because estrictely this is not a change of the modulus value, but a softhening of your sample which exhibit a very low micro-yield point. However dislocations can also contribute to a decrease of the intrinsic modulus because arround the core of dislocations there is an increase of the interatomic distances, which have associated a decrease of the stiffness of the atomic bonding and consequently of the modulus of the material at local scale. So if you have a strongly deformed material (high density of dislocations), you may have a slight decrease of the modulus, in spite that you could have a hardening of the material (increase of the yield point) by work-hardening. Pay attention because there are two different concepts.

Nevertheless, in most of cases, a high hardness is obtained because of the precipitation of hard and stiff phases, as well as because of blockage of dislocations by strong point defects interaction (usually weight atoms) and in those cases you will have also an increase of the modulus.

If the value of the Young modulus is a critical parameter for you computation by FEA, I recommend you to ask some colleague to measure the real modulus of the samples by a vibrating resonant equipment. The resonance frequency of the sample will give you a more reliable value of the modulus than the stress-strain curve.

I hope that my answer could be useful for you.

Dear Dr Jose San Juan,

Thank you very much

For your concern, change in hardness does NOT change the modulus. Modulus is the slope of stress-strain curve. What are you changing by changing the hardness is Yield point. Y (yield) is almost 1/3 of H (hardness), but slope stays the same. Nerdy speaking, changing hardness may change modulus but it is still negligible.

1) Elastic modulus is related to the bond strength and the inter-atomic potential is used to evaluate the elastic modulus of a crystal. Strong correlation exists between elastic modulus and the melting temperature. And further between diffusion and melting temperature. Modulus decreases with increasing temperature. So, for low carbon steel, modulus will not be influenced by the heat treatment (insensitive and will be in the range 200 - 210 GPa). But, the mechanical property such as indentation hardness (like yield stress) is related to resistance to plastic deformation (resistance to motion of dislocations) and the changes in micro-structure can have an effect on mechanical behavior.

Further to add on, say in creep, the creep rate is generally normalized with Diffusivity and stress with either elastic or shear modulus. And on this enough literature do exists (papers by Dorn group such as J.E. Bird etal or by A.K. Mukherjee et al. Also by O.D. Sherby, P.M. Burke, Prog. Mater. Sci. 13 (1967) 325–390. I would recommend at the outset that it would be better go through the book "DEFORMATION-MECHANISM MAPS: The Plasticity and Creep of Metals and Ceramics" by H.J. Frost and M.F. Ashby, Pergamon Press, 1982:- (please use the link if you have access http://engineering.dartmouth.edu/defmech/)

(A) Heat treatment of steel : Lab Report: see link if you have access: http://www.csus.edu/wac/journal/2012/Lance_Final_Draft.pdf.

(B) See wikipedia: http://en.wikipedia.org/wiki/Carbon_steel.

2) However for Cu wires, Young's modulus is shown to vary with wire diameter and is related to double fiber texture. See "Young's Modulus as a Function of Wire Diameter" by GEORGE C. KUCZYNSKI, Nature 165, 562 - 563 (08 April 1950); link: www.nature.com/nature/journal/v165/n4197/abs/165562a0.html and  also (i) Phillips, A. J. , and Smith, A. A. , Proc. Amer. Soc. Test. Mat., 36, (2) 263 (1936). (ii) Barrett, C. S. , "Structure of Metals", 457 (McGraw-Hill Book Co., Inc.).

3) The following may be useful:

(A) Materials Science and Engineering Properties, SI Edition, Book by Charles Gilmore.

(B) Course on mechanical behaviour Materials: see link if you have access: http://www.msm.cam.ac.uk/teaching/partIA/courseD/DH.pdf.

(C) "Symposium on Determination of Elastic Constants":  Issue 129, By American Society for Testing and Materials.

(D) See if you have access: "Effect of heat treatment on mechanical properties of orthodontic SS wires": https://www.jim.or.jp/journal/e/pdf3/43/12/3072.pdf.

(E) "Perspectives in Materials Research" edited by Laurence Himmel, page 283. 

4) If you are interested in further information elastic constants: please see

(i) "Correlation between ultrasonic shear wave velocity and Poisson’s ratio for isotropic solid material", Anish Kumar, T. Jayakumar, Baldev Raj, K.K. Ray, Acta Materialia 51 (2003) 2417–2426.

(ii) Ledbetter HM. Elastic properties. In: Reed RP, Clark AF, editors. Materials at low temperatures. Metals Park (OH 44073): American Society for Metals, 1983. p. 1–45.

Best wishes.

Dear Phaniraj C

Thank you very much

1) You may also see: Chapter 2 on Elastic Behavior in Book on "Mechanical Behavior of Materials", by Thomas H. Courtney, Second Edition.

2) You may see presentation "Investigation of anisotropy in elastic modulus of steel" by Umesh Gandhi Toyota Research Institute, NA. Toyota Technical Center, Ann Arbor, Mi, at workshop on "Addressing key technology gaps in implementing advanced high-strength steels for automotive lightweighting" Feb 9-10 2012.

Please see the link if you have access:- http://www.nist.gov/mml/acmd/structural_materials/upload/Steel-elasticity-variation-study-21012_v2.pdf

3) In this above mentioned presentation: single crystal of alpha iron (ferrite) is anisotropic and E111 = 276 GPa, E100 = 129 GPa and the average value for polycrystal EAverage  = 209 GPa  (Ref: Book on "Mechanical Behavior of Materials", by Thomas H. Courtney). 

Dear Phaniraj C

Thank you very much

I don't know the analysis you are performing nor the heat treatment that you consider. But if your problem is the calculation of residual stresses and distortions due to some heat treatment (quenching, surface treatment, etc.), the small differences of the Young's modulus between the different metallurgical phases are generally neglected. What is important is to take into account yield stresses (and hardening) corresponding to the different phases and that can be very different.

Dear Prabhakar

The modulus of elasticity, is an intrinsic property of the material, i.e. it is structure insensitive, not affected by structural modifications. This is governed by the inter atomic forces of the material.

A heat treatment, or alloy addition can increase or decrease the strength of the metal, its ductility but not the slope of the stress strain curve in the elastic region.

it is only affected by temperature, with an  increase in the operating temperature, the modulus of elasticity decreases.

thanks to all dignitaries for giving great theory behind this .....but i need values of young modulus of steel with respect to temperatures.....is it possible to get me any ware..... in some literature....

Dear Prabhakar,

concerning the temterature dependence of Young's modulus of steel

please see this link: http://www.engineeringtoolbox.com/young-modulus-d_773.html

Concerning the answer by Santosh Kumar, he is rigth. But his answer does not cotradict my answer. In case of martensitic transformation the crystal structures changes to BCT (body centered tetragonal) from austenitic structure, so that the modulus does change. However heat treatments are such that the martensitic transformation is needed to occur only on the surface to increase eventually the hardness. So that only small part of of the material is subjected to crystal structure changes. Finally, the (room temperature) modulus of steel remains bounded between 180 and 210 GPA .

Concerning the Anand request, I suggest the reading of the following paper which gives both thermal and mechanical properties (function of temperature) for the numerical simulation of quenching of a 40CMD8 steel plate. The paper is available on my RG page.

E. Feulvarch, M. Fontaine, J.M. Bergheau, « XFEM investigation of a crack path in residual stresses resulting from quenching », Finite Elements in Analysis and Design, Vol. 75, 2013, pp. 62-70.

 How to define the material (steel) hardness in abaqus FEA software?

I perform 3d printing and coducted some experiment on polymeric (Ethylene Vinyl Acetate) parts and observed that modulus was increasing with the increases in the bed temperature. Can anyone suggest me why is it happening?

@Narendra Kumar,

Since the original question is about steels and yours is about polymers, I'd suggest you ask a new question if you want to have better answers.

Nevertheless, I'd suggests that the increase in modulus is related to an increase in crystallinity of your EVA polymer when the bed temperature increases. I'm not a specialist of 3d printing, but I could see the lower cooling rate of your material and lower temperature gradient as promoting crystallization upon solidification and the crystalline parts are stiffer than the amorphous regions in polymers.

Best regards,

Laurent

The Young Modulus of a material depend on several factors, many of them have been already invoked in previous answers. Just clarify it:

The first point is the kind of bonding: Covalent, metallic, ionic and so on. Consequently each group of materials, ceramics, alloys, ionic crystals, polymers etc exhibit a particular range of values for the young modulus.

The second point is the nature of the elements and the particular potential interaction curve between atoms. So if we consider just pure metals, the value of the young moudulus strongly depend on the element: W (406 GPa), Fe (196 GPa), Ti (116 GPA), Al (69 GPa). Consequently, in the case of alloys formed by solid solutions, each element in solid solution will contribute to increase or decrease the modulus of the alloy. This is clearly applied for steels.

The third point is the phases developed by the different elements, FCC, BCC, HC, etc, with special enphasis in atomic ordered phases, where the direccionality of the bondings could increase the modulus. Tipycally, when performing a heat treatment we change the ammount of phases (with different modulus), and inside each phase we can also change the atomic composition because of the different solubility for each element. This effect will also change the value of the modulus. In this situation a polycrystalline alloy, from the point of view of modulus will be like an agregate of phases with different modulus.

The fourth aspect is the crystalline orientation. Some phases are strongly anisotropic, exhibiting different modulus in different crystallographic directions (up to one order of magnitude). In this case the thermal and mechanical treatments can change the texture of the material, given place to a change in modulus.

Finally, also as commented before, the presence of crystalline defects such as dislocations and grain boundaries also modify the modulus. Then, again a thermal treatment could also change the modulus because of recrystallization, for instance, although the variation is not usually so strong as in the above points.

Best regards

Please can note the Figure below which explain the change in youngs modulus of elasticity with temperature for some of metals and alloys.

The behavior of the elastic moduli of pure and alloy oponentov fundamentally different. The elastic moduli of the pure components is dependent on temperature and pressure. Whereas elastic moduli of alloys depend on temperature, pressure and composition of the single-phase alloys, and also from the appearance or disappearance of phase (in phase transformations), and thus the rate of loading.

That is elastic modules for dynamic or quasi-static loading have different values. Besides changing alloy elastic moduli, in particular the isothermal bulk modulus, while crossing the figurative point corresponding to the total alloy composition through one - two-phase boundary chart sostosniyaniya zvyazano with specific heat jump and the jump coeffisient thermal expansion alloy.

Details description of these effects are described in the articles:

A.L.Udovsky et all. Physics Letters A 72(1):1-4 · June 1979;

A.Udovsky Computer modelling of phase diagrams, thermodynamic properties and structure of multicomponent systems, Izvestiya Akademii Nauk SSSR, Metally N 2, pp. 136-157, 1990

Sorry, the original question of Prabhakar focused on steel.

Even if steel can be considered an alloy for the case in play the composition is fixed. Thus, being dominant the amount of iron the Young's modulus is dominated by iron. The Young's modulus of iron is around 190-210 GPa (depending on the crystalline structure).

The heat treatmens alter the "ultimate" properties not the elastic ones.

At a given temperature and pressure, the Young's modulus of ordered matter is uniquely debited to the intensity of the chemical bond. This the reason why the value of Young's modulus used by Prabhakar is correct. 

From a theoretical point of view, steel is a representative of a multi-component system formed as an interstitial element (carbon) and replacement elements (chromium, nickel and other elements of the substitution) In bcc - or fcc - iron crystal lattice. When heating temperature is approached eutectoid temperature and long-time heat treatment phase transformations start to occur (for example, decomposes into cementite Fe3C) and to form chromium carbides. (for example, decomposes into cementite Fe3C) and to form chromium carbides. These phase transformation will lead to a change in elastic modulus, the Young's modulus in particular;  see example of change in Young's modulus by 40% at 600 C in relation to Young's modulus at room temperature of the steel with a carbon content less than 0.3 mass%  - please, see in Internet  http://www.engineeringtoolbox.com/young-modulus-d_773.html

Changes in Young’s modulus of the Co-31 mass%Ni-19 mass%Cr-10 mass%Mo alloy (Co-Ni based alloy) with cold-swaging, combined with heat-treatment at temperatures from 673 to 1323 K, was investigated to enhance the Young’s modulus of Co-Ni based alloy. After coldswaging, the Co-Ni based alloy, forming h111i fiber deformation texture, shows the Young’s modulus of 220 GPa. Furthermore, after ageing the cold-swaged alloy at temperatures from 673 to 1323 K, the Young’s modulus increased to 230 GPa, accompanied by a decrease in the internal fiction and an increase in the tensile strength. This suggests that the increment in Young’s modulus is caused by a moving of the vacancies to the dislocation cores and a continuous locking of the dislocations along their entire length with solute atoms (trough model). By annealing at 1323 K after cold swaging, Young’s modulus slightly increased to 236 GPa. On the other hand, the tensile strength decreases to almost the same value as that before cold swaging due to recrystallization. These results suggest that the Young’s modulus and the strength in the present alloy are simultaneously enhanced by the continuous dislocation locking during aging as well as the formation of h111i fiber deformation texture.

read more in this ref.

Influence of Cold-Working and Subsequent Heat-Treatment on Young’s Modulus and Strength of Co-Ni-Cr-Mo Alloy

 Takuma Otomo, Hiroaki Matsumoto, Naoyuki Nomura and Akihiko Chiba

Materials Transactions, Vol. 51, No. 3 (2010) pp. 434 to 441

As per my opinion young modulus is the ratio of stress to strain. Howerer, Stress doesn’t affect the heat treatments but strain will be changed. Depending upon temperature and coefficient of thermal expansion.

Heat treatments do not affest the elastic properties but the unltimate properties like strength , hardness and so on.

The elastic modulus o steel is in between 190 and 210 GPa depending on the alloying while the same materials can exhibit strength varying between 400 and 2000 MPa. The elastic modulus of ordered materials depends on the strength of their chemical bond.

the slope is same . Hope this clarifies all above arguments.HT do not change Elastic Modulus

Yes it will change. The modulus of bulk material come with the aggregation of modulii of it's micro constituents. Heat treatment changes the type and morphology of micro constituents. Consequently the modulus of bulk material will also change

Dear Arshad Noor Siddiquee ,

the modulus depends on the chemical bond and the crystalline structure of a material. In steel it is confined between 190 and 210 GPa while the strength can vary between sau 350 anf 2000 MPa. Thus, the ultimate properties are strongly affected by thermal histories while the elastic properties remain almost constant (or slightly vary)

I agree with Alberto D'Amore and @Levent Yagmur ...look at the diagram above I attached.It's important to distinguish between two very different regimes when considering the stress-strain behavior of metals:

(1) The elastic regime and

(2) the plastically deforming regime.

When relatively small stresses are applied to metals, they tend to behave elastically. If you apply a stress it bends a little, and if you then remove the stress it goes back to its original position. Elastic properties of metals depend on the elemental composition of the metal, but they tend to be insensitive to the microstructural details of the metal. Things like dislocations (produced by work hardening a metal) or fine precipitates (which can be produced by age hardening the metal) don't affect the elastic properties of metals like the Young's modulus much since they tend to be a relatively small volume fraction of the overall volume of the metal.

So the question is really why do these microstructural details become so important when the metal starts to plastically strain? When the stress on a metal becomes large enough to plastically stain it, we enter into a very different regime in which the material is undergoing large deformation which is enabled by the movement of dislocations through it. When this starts to happen, then all those little microstructural details in the metal such as grain boundaries, pre-existing dislocations, and fine precipitates become very important because they all act to block the smooth flow of dislocations through the metal. As a result, more stress has to be applied to the metal in order to overcome the dislocation barriers and make the metal plastically flow. That's why work-hardening and precipitation hardening (i.e., "age hardening") are so effective at increasing the yield strength, which is a measure of the stress required in order to make the metal plastically deform.

Elastic Properties (e.g., Young's modulus, Bulk modulus, Poisson's ratio) depend on the elemental composition of a metal but are insensitive to the microstructural details of a metal.

Plastic Properties (e.g., Yield strength, tensile strength, elongation at maximum yield) are sensitiveto the microstructural details of a metal (e.g., grain boundaries, pre-existing dislocation bundles, fine precipitates) because these microstructural features can block the movement of dislocations through a metal which enable the metal to plastically deform.

Young's modulus is about the bonds between neighboring atoms. With an elastic strain, all bonds in that direction are proportionally longer or shorter.

Example:

Maraging steel 350.

Annealed yield strength = 830 MPa. Annealed elongation = 18% ... Annealed Young's modulus = 190 GPa

Aged yield strength = 2300 MPa ... Aged elongation = 4% ... Aged Young modulus = 190 GPa

Yes, elastic modulus depends on inheterent characteristics such as structure and bond. HT also results in change in structure, in case of steel for example the BCC structure changes to BCT when it is converted to martensite

I agree with Mr. Arshad. The E value will change when the steel is thermally excited. Change in properties occur when heat treated due to the change in base matrix.

A.V.Sethuraman

Interesting: question asked 4 years ago and still no consensus!

I feel like people are looking at the problem from different perspectives here. Could it be that in absolute terms there might be a minute change of the modulus due to heat treatment (perhaps of interest for a solid state matter physicist), but that from a practical standpoint it is usually neglected by engineers because it is so small it does not register at the usual level of precision?

I mean, in the original question the modulus is given to a single significant digit. Does anyone really expect heat treatment on a steel to change it from 2E5 MPa to 1E5 MPa or 3E5 MPa?

Otherwise, I guess a scientific paradigm shift is coming as we are witnessing science in crisis as per Kuhn's philosophy :). Happy new year (2019) to all!

Regards,

Laurent

Agree Laurent and several others. The change in strength is remarkable whereas the change is E is small. But, even a small change in E makes considerable difference. Say for example Al and MS of identical geometry are equally loaded such that the failure strain be same. In such a case, may be, MS will fail instead of Al despite the fact that MS may be thrice as strong as Al and E for Al may be very less in comparison to MS. In case of most Al-alloys being strengthened by age hardening, the strengthening comes via very high density minute precipitate wherein the chemistry and structure of the substrate dont change post aging. Hence the change in E is negligible and the strengthening is great. In most steel the HT brings about structural changes in micro-constituent and may cause more change in E viz-a-viz ageing in Al-alloys.

I think that E doesn't change with heat treatment but fy will be increase

Good day Gents

Happy new year.

As most of you may or may not be aware:

Young's modulus depends on interatomic forces...

Therefore heat treatment has luckily (sadly) no effect on E

regards

The heat treatment i think is not change the elastic properties but it affect on plastic reagion.

I agree with Dr Ahmed Saadoon

According comments of all this discussion, Young modulus on steel can be obtained from 190 to 210 Gpa, this means 20 Gpa (20,000 MPa) of range. This range is almost the stiffness offered by some semi-crystalline materials. For mechanical modeling purposes, that difference is significant, also for fatigue bending calculation purposes. In my experience, Young modulus obtained by stress-strain curves on hardened + tempered samples (tempered martensite as microstructure) can have about 5% of variation. Agree with the argument that heat treatment can change a little bit the E, the effect will depend of the kind of steel and the kind of heat treatment. However if you like to looking for the effect of heat treatment on the Young modulus of steels, ASTM E8 is not a good method to get a good conclusion because may be the effect will be lost on the estimation process.

I agee completely with Gordon

We actually did some measurements addressing this question. We put some Al-Cu samples into a DMA and measured the modulus continuously at 1 Hz as the samples were aged. We found that the modulus changed in a manner that correlated with the precipitation of the strengthening phases, but the changes were quite small and were not observed in other alloys. We also found that we were not the first to observe this. In general, modulus follows the rule of mixtures, but small deviations from this occur when intermetallics form that alter the average interatomic separation distance (and the volume changes).

I agree with Dr. Gordon

Each structure has its Young's modulus

so the change of modulus during the heat treatment is necessarily due to a change of structure such that :

- Partial decomposition of the phase

- Phase change

- Hardening phenomenon

- Oxidation (weakening of the material)

There is a very effective technique for monitoring the evolution of Young's modulus: Internal friction

A couple of nice papers addressing composition vs. structure (ordering) in modulus:

C. Li, Y. L. Chin and P. Wua, Intermetallics 12, 103-109 (2004) and C. H. Li and P. Wu, Chemistry of Materials 13 (12), 4642-4648 (2001).

I have already answered this question. E value will change after heat treatment, may not be very significantly

Hi

In addition to the Gordon Livey

SIncerely

Claes

Please see the attached file. It may be helpful.

i agree with Dr Gordon, heat treatment will only change your yield and harding and ultimate stress values, it will also shift material towards a more isotropic behaviour

Dear Dr. Ajibola I agree with you

Thanks

Well, there are different angles to look at this. Now, heat treatment should affect the Youngs Modulus, however it depends on the metal/alloy being heat treated and the type of heat treatment being applied. You should understand that Youngs modulus is a measure of STIFFNESS of metal/alloy. Some alloys that are hard can be heat treated to soften. This is the essence of annealing. At other times, soft/ductile materials can also be hardened by appropriate hardening heat treatment procedures. Apart from heat treatment, design can also be used to control the stiffness of a material. In summary, the whole point of heat treatment is to influence materials properties of which Youngs Modulus is included

it should be change, because the young modulus is the ratio between tensile strength and the tensile strain, so both of them will be affected by heat treatment process.

Free vibration of elastic systems with natural damping and shock are events with very small

duration and, hence, the heat is negligible.

The effect of heating appears in forced vibrations of elastic bodies. This effect is insignificant

if a body has big surface and very small stiffness, for example in vibration of thin plates, due to dissipation of heat in surroundings. In contrast to such elastic bodies, the longitudinal

vibrations of uniform, circular roads, observed on testing machines, revealed the heating up to 600-700 degree C with red color of rods.The analysis and mathematical modeling of elastic

bodies with concomitant heat is devious problem. As a matter of fact, the damping, stiffness

with density of material and Young"s modulus and, therefore, deflection x are changing with

increase of temperature associated with growing number of cycles of vibrations. The temperature as a function of the sum of hysteresis curves areas, which are function of force

F and changing deflections x. Naturally, the dissipation of heat in surroundings also should

be taken into account. Apparently, only qualitative estimate and experimental data are suitable for understanding this event. In technical applications the cooling is used to avoid

excessive heat.

P. S. The dependence of Young"s modulus from temperature for few steels is available online.

The elastic modulus measured under adiabatic conditions differs from the value determined for isothermal conditions. The magnitude of this difference is related to the coefficient of thermal expansion and the loading frequency of the shift is related to the coefficient of heat transfer. Of course, the relationships depend on sample geometry and loading conditions. This is discussed in the book by Nowick and Berry, Academic Press (1972).

At other times, hardening can increase Young's Modulus of steel up to about 300%. I refer you to this article: https://pdfs.semanticscholar.org/371a/2af4bf87215a868799bfad06802a45991fa5.pdf. Generally, heat treatment can significantly alter the mecahnical properties of materials. Even wood properties are significantly altered by heat treatment. Recently, I heat treated some wood materials and the results showed some of the woods have about 100% improvement in their young's modulus.

I had answered this question already. E value will change after heat treatment

provided there is no segregation in the micro.uraman

A.V.Seth

Hi

Yes of-course. No doubt in that .based on the cooling rate only the ductility and toughness get determined.

Yes, l agree with Dr parkash

Yes, you right Dr

Good answer Dr hamed

Dear Prabhakar,

Yes. Scientifically it changes. Principal behind this is vibration of atoms and disappears of dislocation.

Young's modulus as well as the strength increases during aging heat treatment. With the increase of temperature, the material will have a volume expansion. Temperature in the metal can increase the vibration of atoms in the crystal structure, which will increase the atomic distance and decrease the atomic force and this will cause the changes of lattice potential energy and curvature of the potential energy curve, so the Young's modulus will also change. Here dislocations disappear; as a result, the Young's modulus is considered to increase.

Hope it little helpful for you.

Ashish