QT500-7铸铁车轮的断裂失效分析  

Fracture failure analysis of QT500-7 cast iron wheel

作　　者：王保华[1] 卢杉[1] Wang Baohua;Lu Shan(College of Mechanical and Electronic Engineering,Jiaozuo University,Jiaozuo Henan 454000,Chin)

机构地区：[1]焦作大学机电工程学院

出　　处：《金属热处理》2018年第7期238-241,共4页Heat Treatment of Metals

基　　金：河南省科技攻关项目(142102210267)

摘　　要：对用球墨铸铁QT500-7制造的汽车车轮的断口进行了形貌分析和能谱分析,同时进行了理化检测。结果表明：车轮的金相、硬度、球化率均符合技术要求。在心部较厚的部位取拉伸试样,其伸长率不合格,对拉伸试棒的断口进行分析,发现断口上集聚了Mg、Al、Ca、La等球化剂颗粒。但伸长率不合格不是开裂的主要原因。断口裂纹起源于凸台和减重槽交界部位的尖角处,且该处无夹杂物,是由于设计原因引起的应力集中而导致开裂的。The fracture surface of a QT500-7 nodular cast iron automobile wheel was analyzed by morphology and energy spectrum analysis,and tested by physical and chemical methods. The results show that the metallographic,hardness and spheroidization rate of the wheel meet the technical requirements. Tensile specimens were taken at the thicker part of the heart,and the elongation is not qualified. The fracture surface of the tensile bar was analyzed,and found that Mg,Al,Ca and La spheroidizing agent particles are gathered on the fracture surface.However,the unqualified elongation is not the main reason for the cracking. The fracture crack originates from the corner of the junction between the boss and the weight reducing groove,where there is no inclusion. The cracking is caused by the stress concentration caused with the component design.

关 键 词：汽车车轮 球墨铸铁 失效分析 应力集中 

分 类 号：TG245[金属学及工艺—铸造]