东北大学学报:自然科学版 ›› 2015, Vol. 36 ›› Issue (11): 1576-1580.DOI: 10.12068/j.issn.1005-3026.2015.11.013

• 材料与冶金 • 上一篇    下一篇

超快冷下X70管线钢热轧工艺及显微组织

康健1, 赵金华1, 王学强1,2, 邸洪双1   

  1. (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;2. 首钢股份公司 迁安钢铁公司, 河北 迁安064404)
  • 收稿日期:2014-10-15 修回日期:2014-10-15 出版日期:2015-11-15 发布日期:2015-11-10
  • 通讯作者: 康健
  • 作者简介:康健(1982-),男,辽宁沈阳人,东北大学博士后研究人员; 邸洪双(1958-),男,辽宁锦州人,东北大学教授,博士生导师.
  • 基金资助:
    国家科技支撑计划项目(2012BAF04B01).

Hot Rolling Process and Microstructures of X70 Pipeline Steel Under Ultra-Fast Cooling

KANG Jian1, ZHAO Jin-hua1, WANG Xue-qiang1,2, DI Hong-shuang1   

  1. 1.The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China; 2.Shougang Qian′an Iron & Steel Co., Ltd., Qian′an 064404, China.
  • Received:2014-10-15 Revised:2014-10-15 Online:2015-11-15 Published:2015-11-10
  • Contact: DI Hong-shuang
  • About author:-
  • Supported by:
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摘要: 研究了14.2mm X70管线钢轧后经超快冷+层流冷却、层流冷却两种冷却制度后的显微组织及力学性能,讨论了超快冷+层流冷却下实验钢强韧化机制.结果表明:两种冷却制度下实验钢力学性能均满足API SPEC 5L X70要求,超快冷+层流冷却下实验钢强度、塑性及韧性较高,综合力学性能良好;不同冷却制度下显微组织均为贝氏体铁素体+针状铁素体+M-A岛混合组织,其中超快冷+层流冷却下针状铁素体、M-A岛组织更加细化;超快冷+层流冷却下实验钢主要强韧化机制为细晶强化与纳米析出强化;实验钢理想轧后冷却工艺为:820~840℃终轧+超快冷至450~500℃+层流冷却至350~400℃+卷取.

关键词: 超快冷, X70管线钢, 针状铁素体, M-A岛, 热轧工艺

Abstract: The microstructures and mechanical properties of 14.2 mm X70 pipeline steel, which undergoing ultra-fast cooling+laminar cooling and single laminar cooling after finish rolling, were compared and analyzed. The strengthening and toughing mechanisms were discussed for ultra-fast cooling methods. The results indicate that the mechanical properties of the experimental steel at both cooling methods can meet the API SPEC 5L X70 criterions. The microstructures consist of bainitic ferrite, acicular ferrite and M-A island, and the mixture microstructures of acicular ferrite and M-A island can be refined at the condition of ultra-fast cooling+ laminar cooling. The main strengthening mechanisms are grain refinement strengthening and nano-scale precipitation strengthening. The ideal cooling method after rolling for 14.2mm X70 pipeline steel is listed as: finish rolling at temperature of 820~840℃+ ultra-fast cooling to temperature of 450~500℃+laminar cooling to 350~400℃+ coiling.

Key words: ultra-fast cooling, X70 pipeline steel, acicular ferrite, M-A island, hot rolling

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