Hello everyone, I want to find some information about using this type of heat treatment in HSLA or DP. Especially, I need sth about microstructure after it and mechanical properties. Is it true that is impossible to hardened steel which contains less than 0,22% carbon?
For very low carbon steels (hypo-eutectoid< 0.8%C), on quenching, the BCT (Body centered Tetragonal) structure of Martensite (transformed from pre-eutectoid austenite) resembles BCC of alpha-ferrite. Hence not much improvement in hardness is observed.
With increase in carbon %, the BCT cell height increases and thus deviates from the BCC of alpha-ferrite. Therefore hypereutectoid steels are more responsive to hardening/ quenching treatments.
Hi, Its of low to carbon steel which is 0.06–0.15 wt.%C and has Cr & Mo stabilize the austenite. so regarding of this facts the laser surface treatment do nothing with the surface characteristic .
Just trying to address the second question... Generally, there are two mechanisms of hardening when quenching Fe-based alloys: 1. Distortion of crystal lattice during shear transformation (fast cooling, diffusion is suppressed). 2. Distortion of crystal lattice due to excessive carbon in it.
So, even at very low carbon content in steel we have #1 mechanism in action. Therefore, it is theoretically possible to quench even pure Fe. But in this case we have to cool very fast to suppress the diffusion transformation. Although, this may be possible with laser quenching.
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Annealing
- Metallurgy