摘要
我公司采购的辐板辊材质为5CrMnMo,在精加工时发现在截面变化的根部有周向分布的环状裂纹,占圆周1/3以上,裂纹为相邻两条,大部分区域位于变截面几何点,边缘向筒体偏离约10mm。通过宏观分析、化学分析、微观试验分析、扫描电镜断口观察等分析了周向裂纹产生的原因。结果表明辐板辊开裂属调质过程中产生的淬火裂纹。淬火开裂主要原因系淬火应力偏大所致,可能的因素系淬火出油温度低,未及时回火等原因造成;此外,半粗加工变截面处无圆角过渡,也增大应力集中系数,对开裂有促进作用。
Circular cracks with circumferential distribution were found at the root of the section change in 5CrMnMo spoke roller purchased by Taiyuan heavy Rail Transit Equipment Co., Ltd. during finish machining. The cracks were two adjacent ones distributed around the circle and occupy more than 1/3 of the circle. Most of the crack areas were located at variable cross-section geometric points, with edges deviating about 10 mm from the cylinder. The objective of this study was to analyze the causes of circumferential cracks by means of macro-analysis, chemical analysis, micro-test analysis and SEM fracture observation. It was indicated that the cracking of the spoke roller was a quenching crack during quenching and tempering. The main reason of quenching cracking was the large quenching stress caused by low quenching oil temperature, non-timely tempering and so on. Besides, the non-fillet transition at the variable cross-section of semi-rough machining would also increase the stress concentration factor and thus promote the cracking.
作者
王旭东
Wang Xudong(Taiyuan Heavy Industry Railway Transit Equipment Co.,Ltd.,Taiyuan 030000,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2019年第S01期164-168,共5页
Heat Treatment of Metals
关键词
辐板辊
周向裂纹
变截面
淬火裂纹
应力集中
spoke roller
circumferential crack
variable cross-section
quenching crack
stress concentration
