微张力对不锈钢/碳钢界面复合质量及原子扩散的影响  

Effect of Micro-tension on Interfacial Composite Quality and Atomic Diffusion of Stainless/Carbon Steel

作　　者：刘鑫 帅美荣[1] 李海斌[1] 谢广明[2] 常彬彬[1] 李亮[1] LIU Xin;SHUAI Meirong;LI Haibin;XIE Guangming;CHANG Binbin;LI Liang(Engineering Research Center of Heavy Machinery Ministry of Education,Taiyuan University of Science and Technology,Taiyuan 030024,China;State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang,110004,China)

机构地区：[1]太原科技大学重型机械教育部工程研究中心,太原030024 [2]东北大学轧制技术及连轧自动化国家重点实验室,沈阳110004

出　　处：《材料导报》2022年第23期123-128,共6页Materials Reports

基　　金：国家自然科学基金(52075357);山西省重点研发计划(201903D121043);轧制技术及连轧自动化国家重点实验室(东北大学)开放课题(2020RALKFKT013);山西省研究生教育改革研究课题(2020YJJG241);山西省研究生教育创新项目(2021Y709)。

摘　　要：随着绿色可持续化工业进程的推进和人类资源开发向海洋的转移,耐腐蚀钢筋市场需求量逐渐提高。本工作采用有限元仿真技术建立不锈钢/碳钢复合钢筋四道次连续轧制模型,深入研究不同轧制工况对复合钢筋覆层壁厚均匀度以及界面“空洞”缺陷的影响;通过加载拉应力工况建立COMPASS力场下的界面模型,探究复合钢筋界面原子扩散行为。宏/微观模拟研究表明:微张力轧制会促使双金属界面形成“空洞”,但能显著抑制轧制过程中“耳子”缺陷的产生;拉应力(微张力)升高有效促进了界面沿(111)晶面滑移,并产生了有序度高且一致的界面结构。复合界面微观组织试验同样表明,在高温高压微张力作用下,界面元素过渡平缓,金属碎粒与孔洞消失;近界面区域主要为铁素体晶粒,且越靠近界面珠光体含量越少,渗碳作用越明显。本研究有助于揭示不锈钢/碳钢高压微张力复合过程中金属流动规律及界面原子迁移机制,为优化复合工艺奠定理论基础。With the advance of industrial process of the green and sustainable feature and the transfer of human resources development to sea engineering, the market demand for corrosion-resistant steel bars is gradually increasing. In this work, the continuous rolling models of four passes for stainless/carbon steel were established by finite element simulation. The effect of different rolling conditions on the wall thickness uniformity of the coating metal and the interface cavity were deeply analyzed. The interface models under COMPASS force field by loading the tensile stress were employed to explore the diffusion mechanism of interface atoms. The results from macro and micro simulation show that the micro-tension rolling can promote the formation of cavity in the bimetal interface. However, it is positive to significantly restrain the appearance of ‘ear’ defects during the rolling process. The increase of tensile stress(micro-tension) could effectively promote the interface slip along the(111) crystal plane, which produces a high and consistent order of the interface structure. The experimental results from micro-structure indicate that the transitions of metallic elements are gentle, and metal impurities as well as holes disappear. The interface is starting towards integration under the action of high temperature, high pressure and micro-tension. There is a large number of ferrite grains in the near interface area. The closer the interface, the less the content of pearlite, and the carburizing action is obvious during this process. This research helps to reveal the flow law of metals and the migration mechanism of interface atoms during the composite process of dissimilar metals, which would provide the theoretical foundation for optimizing the process.

关 键 词：微张力 界面复合 原子扩散 实验研究 

分 类 号：TG335.82[金属学及工艺—金属压力加工]