热处理对GCr15钢冷模具多次冲击抗力的影响

本文对原始組織经过高温固溶碳化物细化预处理,再通过控制马氏体形态的低温短时加热淬火;碳化物細化加奥氏体超細化的四次循环快速加热淬火;球化加常规工艺淬火等工艺处理的GCr15钢进行了多次冲击弯曲试验,研究了GCr15钢在不同热处理状态下的多次冲击弯曲抗力变化规律。根据对多冲试样断口的微观分析,研究了GCr15钢不同热处理工艺多冲抗力变化的微观机理。试验結果表明,经高温固溶碳化物細化预处理加奥氏体超细化的四次循环快速加热淬火的GCr15钢,多次冲击弯曲坑力在任何能量下,均比其他工艺高。微观断口由常规工艺的准解理加解理断裂变为准解理加韧窩断裂。用这种工艺处理冷冲、冷镦模具,可以大大提高其使用寿命。

The Influence of Heat Treatment on Resistance to Multiple Impact of Cold Work Die Made of GCr15 Steel

The paper researches the variation of resistance to multiple impact bend of GCr 15 steel with heat treatment process by means of multiple impact-bend test for GCr15 steel treated by various multistage heat treatment including high temperature solution treatment to refine carbide, low temperature rapid heating and quenching to control morphology of martensite, four cycle rapid heating and quenching to refine carbide and super-refine austenite grain, as well as nodulizing and conventional quenching process etc.. The mechanism of variation of resistance to multi-impact of GCr 15 steel with heat teratment process was also studied on the basis of the analysis of micro morphology of multi-impact specimen fracture. The results show that the resistance to multiple impact bend of GCr 15 steel treated by high temperature solution to refine carbide plus four cycle rapid heating and quenching to super-reflne austenite grain is higher than that treated by other treatment processes under any energy. The fracture mode changed from quasi-cleavage plus cleavage obtaioed from conventional treatment to quasi-cleavage plus dimple. The service life of cold punching die and cold heating die treated by this process is greatly increased.