东北大学学报:自然科学版 ›› 2018, Vol. 39 ›› Issue (11): 1588-1592.DOI: 10.12068/j.issn.1005-3026.2018.11.014

• 材料与冶金 • 上一篇    下一篇

在线控冷对热轧L360管线管组织和性能的影响

李振垒, 陈冬, 康健, 袁国   

  1. (东北大学 轧制技术及连轧自动化国家重点实验室, 辽宁 沈阳110819)
  • 收稿日期:2017-08-10 修回日期:2017-08-10 出版日期:2018-11-15 发布日期:2018-11-09
  • 通讯作者: 李振垒
  • 作者简介:李振垒(1984-),男,河南濮阳人,东北大学博士后研究人员; 袁国(1979-),男,山东泰安人,东北大学教授,博士生导师.冯明杰(1971-), 男, 河南禹州人, 东北大学副教授; 王恩刚(1962-), 男, 辽宁沈阳人, 东北大学教授,博士生导师.
  • 基金资助:
    “十二五”国家科技支撑计划项目(2012BAF04B01); 中国博士后科学基金资助项目(2015M581347).

Effect of Online-Cooling on Microstructure and Mechanical Properties of Hot-Rolled L360 Steel Pipe

LI Zhen-lei, CHEN Dong, KANG Jian, YUAN Guo   

  1. The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China.
  • Received:2017-08-10 Revised:2017-08-10 Online:2018-11-15 Published:2018-11-09
  • Contact: LI Zhen-lei
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摘要: 针对热轧无缝钢管组织性能调控手段单一,依赖添加合金元素和离线热处理的问题,以轧板模拟轧管的方式,通过实现在线控制冷却将离线热处理工艺在线化,研究分析了热轧L360高温轧制后在线控冷条件下显微组织演变及力学性能变化规律.结果表明:高温轧制后空冷时实验钢中含有粗大的魏氏组织,而轧后控制冷却工艺下实验钢组织显著细化,有利于微合金碳氮化物析出.实验钢轧后控冷至650℃时,能够避开魏氏组织形成的区间,同时屈服强度为478MPa,抗拉强度为641MPa,伸长率达到25.3%,屈强比0.74,0℃冲击功高达164J,实现了强度、韧性和塑性的平衡,各项力学性能指标均能满足API SPEC 5L—2012标准要求.

关键词: 热轧L360管线管, 魏氏组织, 显微组织, 力学性能

Abstract: In the view of the hot-rolled seamless steel pipe problems which lacks the way to control microstructure and mechanical properties, depends on the addition of alloying element excessively and uses an off-line heat treatment, an online cooling after rolling treatment is used to replace off-line treatment by means of the plate rolling instead of tube rolling. The effects of different cooling strategy on the microstructure and mechanical properties of a typical hot-rolled L360 steel pipe is studied. The results show that compared with air cooling treatment which easily causes a coarse Widmanstatten structure in L360 steel, the cooling after rolling treatment can promote the precipitation of microalloying elements, refine Widmanstatten structure and improve mechanical properties of the steel. When cooling temperature is controlled at 650℃, the formation of Widmansatten structure is reduced effectively and the balance of strength, toughness and plasticity of L360 steel can be achieved with the yield strength of 478MPa, the tensile strength of 641MPa, the elongation of 25.3%, the yield ratio of 0.74 and the impact energy at 0℃ of 164J, respectively, which meet the requirements of the standard of API SPEC 5L—2012.

Key words: hot-rolled L360 steel pipe, Widmanstatten structure, microstructure, mechanical property

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