原始组织及退火工艺对SCM435盘条退火行为的影响.pdf

总第240期
炳金
Total No 240
2015年第12期
HEBEI METALLURGY
2015. Numberl2
试验研究
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原始组织及退火工艺
对SCM435盘条退火行为的影响
田新中,王利军,陈继林,瞿进坡,冯忠贤,王宁涛
(邢台钢铁有限责任公司河北省线材工程技术研究中心,河北那台054027)
摘要:分析了低温轧制工艺、低温+缓冷工艺及正常轧制工艺生产的SCM435盘条的显微组织,研究了
不同原始组织及退火工艺对SCM435碳化物球化行为的影响。研究结果表明:低温轧制工艺得到的多
边形铁素体、珠光体、贝氏体及少许马氏体组织不利于获得均匀分布的球状珠光体;加热温度、加热时
间、等温温度及等温时间同样对碳化物球化有较大影响。试验研究得出SCM435退火合适工艺参数:加
热温度760℃,保温1.5h,并随炉冷却到720℃保温5h,然后随炉冷却到550℃以下出炉空冷
关键词;盘条;原始组织;球化退火;球化率
中图分类号:TG142.4
文献标识码:A
文章编号:1006-5008(2015)12-000-05
doi:10.13630/j.cnki.13-1172.2015.1202
IINFLUENCE OF ORIGINAL STRUCTURE AND ANNEALING
PROCESS ON ANNEALING BEHAVIOR OF SCM435 WIRE BAR
Tian Xinzhong, Wang Lijun, Chen Jilin, Zhai Jinpo, Feng Zhongxian, Wang Ningtao
(Wire Engineerin Technique Research Center of Hebei Province, Xingtai Iron and Steel Company, Xin tai
Hebei,054027)
Abstract: It is analyzed the micro structures of SCM435 wire bar prouced separately with low-temperature
rolling low-temperature rolling plus slow-cooling process or normal rolling process, researched the influ-
ences of different original structure and annealing process on nodulizing behavior of carbide of SCM435 steel
It is showed from the research that the poly on femi, pearlite, bainite and a little martensite structure got in
low-temperature rolling process are bad for obtaining homogeneously distributed globular pearlite; and heat-
ing temperature, heating time, temperature-keeping temperature and time also have large influence on car-
bide nodulizing. The appropriate annealing process parameters for SCM435 steel are got in test heating tem
perature 760 C, keeping for 1. 5 hours, cooled along with furnace down to 720 t and keeping for 5 hours
and then cooled along with furnace down to below 550 C and exited out to cooled in air
Key Words: wire bar; raw structure; nodulizing annealing; nodulizing rate
0引言
素,采用常规轧制工艺生产的盘条,显微组织存在大
低合金冷镦钢SCM435热轧盘条,主要用于制量的贝氏体、马氏体和部分铁素体、珠光体,且组织
作10.9~12.9级高强度级别螺栓、螺母、螺钉等柝较为粗大,即使退火后,也不能消除组织不均及粗大
准件。一般由热轧盘条经软化退火、一次拉拔、球化问题,对产品冷徽成形产生不利影响。因此,研究热
退火、二次拉拔、冷镦成形及调质处理等工艺制成,轧盘条原始组织及退火工艺,提高产品塑性变形能
其中退火是螺栓生产工序中耗能、耗时最多的工力,具有重要的意义。本文从原始组织及退火工艺
序?。由于SCM435含有较多提高淬透性的合金元两方面着手,研究了原始组织及退火工艺对
SCM435球化退火效果的影响。
收稿日期:2015-09-29
试验材料及方法
作者简介:田新中(1968-),男,博士,教授级高工,现为邢台钢铁有
限资任公司副总工程师,E-mlil:wujun604@126.com
采用不同轧制工艺生产的SCM435盘条作为试
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