If any one has the solution or any idea to approach to the solution, kindly suggest. It would be highly appreciated............

Using with dta or tga find ac3 ac1 ac4 temperature , tampered below ac3 temperature ,holding time 1 hour ,air cool to room temperature ,

@ Gavinola Srinivasreddy:

Thanks for your response.

The treatment you suggested is a simple "intercritical annealing" treatment and is mainly used to get some desired microstructure at the end of thermal cycle; It is not used for the homogenization of the chemical composition or microstructure. I am looking for some definite way to calculate the amount of deformation at any given temperature (in austenitic phase regime) and the holding time required to get a almost homogeneous microstructure (to get rid of cast structure) and chemical composition (that can be verified by means of EDX line scan).

I doubt that there is any reliable "rule-of-thumb" to determine the perfect set of variables to effect absolute homogenization. There are certainly Industry practices, but they will be dependent on the expected inhomogeneities (chemical, inclusions, segregation) that need to be reduced. Using vacuum arc remelting (VAR) or electroslag remelting (ESR) are accepted ways to get low segregation in the starting ingot and thus reduce reliance on thermal or deformational post-processing. You might want to contact the Heat Treat Society of ASM International and post your question on their website to get insight into common practices.

You have different aspects. I am assuming that you have strong microssegragation after solidification. In this case the diffusion annealing for homogenization must be done close to the solidus line of the steel alloy, 50 to 100oC below, and use time from 24 to 48 hours depending on the material size and weight. Hot deformation is usefull because reduces the interdendritic spacing and increases the homogenization rate. You can use both process together.

Thanks for all your response and fruitful discussions.

Hi Ravi

I am looking for suitable time and temperature for my samples. I would decide use 1200 for 2 days but with respect to increase possibility of oxidation even I sealed sample and also kiln efficiency I would prefer time and temperature. my sample is high carbon steel and composition is near to tools steel . do you have any idea or suggestion ?

Hello Zeinab,

Which element(s) do you have in maximum (e.g., Mn, Cr, etc.) and what size of the sample are you planning to perform the treatment on?

man is 0.98 cr is 0.67 C is 1 percent and other element are less than 0.2 percent. The size of sample is different from dilatometry sample ( 10 mm * 5 mm) up to maximum 60*60. I would be appreciate if introduce me any reference to calculate and predict homogenization. In addition, I could not see your response I am not familiar with research gate .

There is no direct way to run detailed calculations. The data for the diffusivity are limited for the multi-component system.

One quick calculation that can be performed though is: take the diffusivity of the element that has the lowest diffusivity and calculate the time for your sample size using Fick's second law. This should give you rough idea about the minimum time required.

Later on you can check the homogeneity of your sample through EDS, WDS and/or EPMA.

many thanks I used 950 for 1 hour and check composition of different point with spectroscopy and they have differences less than 1% just the measurmenthas different more than 10 percent for P and S. Is it possible that I refer to this data for prove that is is homogenize or not?

Spectro. gives you the average composition of the bulk. I am not too confident if you can take these data as the confirmation of homogeneous distribution of elements. The better way would be to perform atom mapping and/or line scan using EDS/WDS.