附板折弯开裂的原因及预防措施
Cause of Cracking of Attached Plates during Bending and Precaution
陈立鹏 1尚召华 2王绪珍 1金强光1
作者信息
- 1. 青岛征和工业股份有限公司,山东 青岛 266705
- 2. 青岛征和工业股份有限公司,山东 青岛 266705;青岛市链传动重点实验室,山东 青岛 266705
- 折叠
摘要
农机链用 40Mn钢附板通过折弯成形.一批直附板在冲压成形和去应力退火后折弯至 90°时开裂.为揭示附板折弯开裂的原因,对开裂的附板和原材料进行了宏观分析、化学成分分析、硬度检测和金相检验;复查了去应力退火工艺;对直附板进行了调质处理而不再进行去应力退火.结果表明:附板的原组织为铁素体、球状珠光体和少量片状珠光体,符合要求;去应力退火后附板组织为铁素体和片状珠光体,塑性较差,从而折弯成形时开裂;直附板的片状珠光体是去应力退火温度升高到了800℃所致;调质处理的直附板组织为回火索氏体,塑性良好,折弯成形时没有开裂.
Abstract
The 40 Mn steel attached plate for agricultural machinery chain is to be formed by bending.A batch of direct attached plate cracked at the time of being bent to 90° after stamping and stress relieving.To reveal the reason why the attached plates cracked during bending,the cracked attached plate and the raw material were subjected to macro-analysis,chemical composition analysis,hardness measurements and metallographic examination.The reinspection of stress relieving process was performed.The direct attached plate was quenched and high-temperature tempered and was stress relieved no longer.The results showed that(a)the prior structure of the attached plate consisted of ferrite,spheroidal pearlite and a small amount of lamellar pearlite which conformed with the requirement;(b)the attached plate after stress relieving exhibited microstructure consisting of ferrite and lamellar pearlite whose plasticity was poor,thus cracked during bending forming;(c)the lemellar pearlite in the direct attached plate stemmed from a rise to 800℃in stress relieving temoperature;and(d)after quenching and high-temperature tempering the direct attached plate exhibited microstructure consisting of tempered sorbites thereby had good plasticity,did not cracked during bending forming.
关键词
去应力退火/调质/球状珠光体/折弯Key words
stress relieving/quenching and high-temperature tempering/spheroidal pearlite/bend引用本文复制引用
出版年
2024
NETL
NSTL
万方数据