CA15不锈钢铸件叶轮热处理工艺改进

Improvement of heat treatment process of CA15 stainless steel casting impeller

结合铸造叶轮生产工艺流程,研究了铸造、退火、淬火及淬火+回火条件下CA15马氏体不锈钢铸材的性能。结果表明该材质铸造和1020℃淬火情况下硬度分布在39.5~41.5HRC之间,断后伸长率仅有3%,材质硬而脆不适合整形。在780℃退火+650℃高温回火条件下硬度最低为217~224HBW,室温冲击值为25.7J,韧性较好适合变形量大的粗整形。在1020℃淬火+600℃回火的性能热处理条件下硬度为275~288HB,室温冲击值为23J,韧性适中适合变形量小的精整形。依据材质试验情况进行工艺改进,不仅解决了CA15马氏体不锈钢铸造叶轮整形开裂问题,而且缩短了工艺周期、提高了生产效率。

Combined with the production process of cast impeller,the properties of CA15 martensitic stainless steel castings under the conditions of casting,annealing,quenching and quenching+tempering have been studied.The results show that the hardness distribution of this material is between 39.5 and 41.5 HRC under the condition of casting and 1020℃quenching,and the elongation after fracture is only 3%.The material is hard and brittle and is not suitable for shaping.Under the condition of annealing at 780℃and high temperature tempering at 650℃,the hardness is at least 217~224HBW,and the impact value at room temperature is 25.7J,while the toughness is better for rough shaping with large deformation.Under the performance heat treatment conditions of 1020℃quenching+600℃tempering,the hardness is 275~288HB,the impact value at room temperature is 23J,and the toughness is moderate and suitable for fine shaping with small deformation.The process improvement according to the material test situation not only solves the problem of shaping and cracking of the CA15 martensitic stainless steel casting impeller,but also shortens the process cycle and improves the production efficiency.