摘要
建筑施工用的QT45型塔机支承座在拖运过程中发生断裂。用化学分析、金相检验和热处理工艺试验等方法,对断裂支承座进行了分析。结果表明,铸钢件支承座碳含量严重超标,导致其与走轮轴焊接时脆性开裂敏感性增大而产生热裂纹;同时支承座毛坯在退火时,未严格按退火工艺执行,使其晶粒粗大,铁素体沿晶界呈网状析出,降低材料强度,最终导致支承座断裂。
The left bearing support of the QTZ45 tower machine used in structural building was fractured in operation. By means of chemical composition analysis, metallogical examination and heat-treatment technology testing, the bearing support was analyzed. The results showed, that the carbon content of cast steel bearing support is out of specification. So, when it was welded with the wheel axle, the thermal crack occured. In the anneal process, lecause of the anneal technology is improper, it caused the grain being coarse. Finally, the material strength was decreased, and it caused the bearing support fracture.
出处
《理化检验（物理分册）》
CAS
2004年第7期354-355,378,共3页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
关键词
支承座
材料成分超标
显微组织
失效
退火处理
Bearing support
Material composition is out of the specification
Microstructure
Failure
Anneal treatment
