摘要
通过精铸热锻模的应用及对失效形式、工况条件的分析和性能测试 ,探讨精铸热锻模具钢的强韧性与早期脆断的关系。结果表明 ,精铸热锻模早期脆性断裂往往是由于热处理不当和操作不合乎要求引发的内应力与显微裂纹等所致 ,精铸热锻模具钢低的冲击韧度不是导致早期脆性断裂的根本原因 ,通过材料和工艺的改进 ,精铸热锻模早期脆性断裂是可以避免的。
Early brittle fracture is an important failure pattern of cast dies, which leads to lower life and instability of cast dies. Through application of hot-forged cast dies,analysis of operating modes and failure and evaluation of properties, the relation of early brittle fracture with strength and toughness of cast die steel was studied and the real cause of early brittle fracture found. In most cases, hot-forged dies bear small-energy muti-impact load. Such load usually results in impact fatigue fracture, but not early impact fracture. Cast dies generally possess relatively high service life because of its high resistance to fatigue crack propagation. The early brittle fracture is attributed to internal stress and micro-crack resulted from abnormal cases, such as abnormal heat-treatment and operation. Low impact toughness of cast die steel is not essential cause of early brittle fracture. Through the improvement of materials and processes, early brittle fracture can be avoided.
出处
《机械强度》
CAS
CSCD
北大核心
2004年第4期436-438,共3页
Journal of Mechanical Strength
基金
国家计委产业化前期关键技术与成套设备研制开发项目 (1 99931 7)~~
关键词
热锻模
铸钢
强韧性
早期断裂
Hot forged die
Cast steel
Strength and toughness
Early brittle fracture
