ASTM P20钢塑料模具开裂原因分析  

Cracking reason analysis of ASTM P20 steel plastic mold

作　　者：金林奎 欧海龙 邹文奇 廖森梁 卢景峰 

机构地区：[1]广东省东莞市质量监督检测中心,广东东莞523808 [2]国家模具产品质量监督检验中心,广东东莞523808

出　　处：《金属热处理》2018年第2期239-244,共6页Heat Treatment of Metals

摘　　要：通过扫描电镜断口检查及显微组织分析对ASTM P20钢塑料模具开裂的原因进行了研究。结果表明,该模具产品在热处理过程中,经过了二次重复淬火,在两次加热淬火之间没有进行中间退火,因而形成晶粒特别粗大的组织,致晶界强度以及马氏体位向板条的片间结合力急剧降低,在热应力的作用下,优先在应力集中较大的直壁拐角部位产生裂纹,并快速扩展至40 mm深的粗大裂纹,导致模具失效。The cracking reason of ASTM p20 steel plastic mold was investigated by using scanning electron microscopy fracture examination and microstructure analysis. The results show that the mold product was subjected to a secondary quenching during the heat treatment, and there was no intermediate annealing between the two quenching processes, thus forming a particularly coarse structure, leading to that the grain boundary strength as well as the inter-lath binding force of martensite decreased sharply, cracking occurred in the straight wall comer with higher stress concentration under the action of thermal stress, then quickly extended to 40 mm deep cracks, finally resulting in the mold failure.

关 键 词：ASTM P20钢 塑料模具 二次淬火 解理断裂 晶间弱化 应力开裂 

分 类 号：TG147[一般工业技术—材料科学与工程]