As known, intensive quenching (IQ) process generates high surface compressive residual stresses which are compensated by core tensile residual stresses. If in the core of steel parts are inclusions or defects, these tensile stresses definitely will be a reason for crack formation inside the steel parts. What about creation of neutral surface residual stresses during intensive quenching of steel parts?
It can be done by two ways:
1. By delaying martensite transformation during intensive quenching using self - regulated thermal process.
2. By adjusting water flow velocity during IQ process.
However, I'm not sure that processes can be precisely controlled since many parameters require further investigations and should be double checked.
I think that numerical simulation of the quenching process can be very helpful for that kind of study. May be the following paper which relates the numerical simulation of a crack propagation after quenching could interest you.
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.
Thaks Prof. Bergheau. Numerical simulation of the quenching process really can be very helpful for that kind of study. However , the issues here are the boundary conditions, especially during transient nucleate boiling process. In heat treating industry, engineers and well known scientist use for FEM calculations effective heat transfer coefficients(HTCs) instead of real HTCs. In this case FEM calculations provide incorrect data, especially at the surface layers of steel parts during quenching. Effective HTC can be used only for core cooling time calculations of steel parts during quenching. The main attention should be paid to self - regulated thermal process and its duration. In many cases, based on self - regulated thermal process, the first type of boundary condition can be used. In this case resuls of calculations are more accurate, with the accuracy +(-) 3% and less.
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