摘要
采用台车热处理炉对AISI 8630空心管进行调质处理可以获得良好的综合力学性能,但调质后沿锻造方向出现纵向裂纹,该裂纹由空心管外表面向心部扩展。通过采取金相显微镜、布氏硬度计、直读光谱仪等测试仪器检测空心管的微观组织、硬度和化学成分等指标。结果表明:该空心管裂纹是淬火裂纹而非锻造裂纹。经过进一步分析,认为原因是在合金元素C超标,淬火冷却速度过快,倒角处应力过大等因素综合作用下,由淬火后的残余组织应力引起的由外表面向心部纵向开裂的现象。
AISI 8630 hollow pipe subject to quenching and tempering heat treatment in bogie-hearth heat treatment furnace can obtain good mechanical properties. However, longitudinal cracks generate along the forging direction and propagate from the external surface to the center. The microstructure, hardness and chemical composition of the hollow pipe were tested with metalloscope, Brinell hardness tester and direct reading spectrometer. The test results reveal the cracks on the hollow pipe are generated by quenching treatment rather than forging operation. The further analysis find out the cracks propagation from the external surface to the center is caused by the residual stress after quenching under combined action of over-limit alloy element C content, higher quenching rate and higher stress on the chamfer.
出处
《一重技术》
2017年第6期62-64,共3页
CFHI Technology
作者简介
隆英（金坛）机械制造有限公司助理工程师
