球化退火对CrWMn钢组织与性能的影响

Effect of Spheroidizing Annealing on Microstructure and Properties of CrWMn Steel

CrWMn钢为冷作模具钢,要求具有高的硬度、耐磨性以及韧性。其最终热处理通常为淬火和低温回火。为了改善切削加工性能,在最终热处理前需要进行球化退火处理。本文对CrWMn钢分别进行常规球化退火、等温球化退火和循环球化退火处理,然后再进行淬火和低温回火处理。比较其最终热处理后的组织,硬度和冲击韧性的大小。结果表明,CrWMn钢经过常规球化退火,淬火和低温回火处理后具有较高的硬度,但是冲击韧性较差。而采用循环球化退火,淬火和回火后会得到综合的机械性能。实验结果对于制定热处理工艺,优化工艺参数,都具有一定的指导意义。

As cold working die steel, CrWMn steel requires high hardness, wear resistance and toughness.The final heat treatment is usually quenching and low temperature tempering.In order to improve the cutting performance, spheroidizing annealing is required before final heat treatment.In this paper, CrWMn steel is treated by conventional spheroidizing annealing, isothermal spheroidizing annealing and cyclic spheroidizing annealing respectively, followed by quenching and low temperature tempering.The microstructures, hardness and impact toughness after final heat treatment were compared.The results show that CrWMn steel demonstrates higher hardness, but poor impact toughness after conventional spheroidizing annealing, quenching and low temperature tempering treatment.Cyclic spheroidizing annealing, quenching and tempering can result in comprehensive mechanical properties for CrWMn steel.The experimental results have certain guiding significance in formulating heat treatment process and optimizing process parameters.