Experiments were conducted to evaluate the microstructure and tensile properties of a medium carbon Cr–Ni–W–Mo steel processed by thermo-mechanical controlled processing (TMCP) with cooling at different conditions in water, oil, air or lime followed by low tempering. Compared to normal heat-treatment processing, TMCP with water-cooling after deformation enhances the yield strength and tensile strength of the steel by ~ 323 MPa and ~ 251 MPa, respectively, due to higher dislocation strengthening and grain boundary strengthening. Meanwhile, it increases the elongation by ~ 1.76% attributed to the increase in volume percentage of the retained austenite and the refined laths of tempered martensite. Slowing the cooling rate after deformation during TMCP leads to a decrease in the strength. This results from the coupling effects by the reduction in dislocation density and volume fraction of tempered martensite together with the coarseness in martensite sizes. However, cooling rate decreasing has less influences on ductility because the improved elongation from the increase in the volume fractions of both retained austenite and lower bainite together with dislocation density decreasing is compensated by the reduced elongation from coarsened grains.

进行了实验，以评估通过热机械控制工艺（TMCP）在不同条件下在水，油，空气或石灰中进行冷却，然后进行低回火进行冷却的中碳Cr-Ni-W-Mo钢的组织和拉伸性能。与常规热处理工艺相比，变形后经过水冷的TMCP可以使钢的屈服强度和拉伸强度分别提高〜323 MPa和〜251 MPa，这归因于更高的位错强化和晶界强化。同时，由于残余奥氏体和回火马氏体精炼板条的体积百分比增加，其伸长率增加了约1.76％。在TMCP期间变形后冷却速度的降低导致强度降低。这是由于降低回火马氏体的位错密度和体积分数以及马氏体尺寸的粗糙度而产生的耦合效应。但是，冷却速度的降低对延展性的影响较小，这是因为残余奥氏体和下部贝氏体的体积分数增加而改善的伸长率，以及位错密度的降低都被粗晶粒的降低的伸长率所补偿。