1. Carbon is an important factor affecting the tendency of quenching. The carbon content increases, the MS point decreases, and the quenching tendency increases. Therefore, under the condition of satisfying basic properties such as hardness and strength, a low carbon content should be selected as much as possible to ensure that it is not easy to quench.
2. The influence of alloy elements on the quenching tendency is mainly reflected in the influence of quenchability, MS point, grain size growth tendency and decarbonisation. The influence of alloy elements on quenchability affects the quenching tendency. Generally speaking, the quenchability increases, but while the quenchability increases, the quenching medium with weak cooling capacity can be used to prevent the deformation and cracking of complex parts by reducing quenching deformation. Therefore, for parts with complex shapes, in order to avoid quenching cracks, it is a better scheme to choose steel with good quenchability and use quenching media with weak cooling capacity.
The alloy element has a greater impact on the MS point. Generally speaking, the lower the MS steel, the greater the quenching tendency. When the MS point is high, the martensite generated by phase transition may be immediately tempered, thus eliminating part of the phase transition stress and avoiding quenching. Therefore, when the carbon content is determined, a small amount of alloy elements or steel with less impact on MS points should be selected.
3. When choosing steel, overheat sensitivity should be considered. Overheating and sensitive steel is easy to produce cracks, so attention should be paid to when selecting materials.
