Effect of cooling mode on transformation plasticity and residual stress of NM400
FANG Yu1, DING Wen-hong1, LIANG Liang2, WANG Jing2, LU Xiao-xuan1, PENG Chong3
1. The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 2. Technical Center, Hunan Valin Lianyuan Iron and Steel Co., Ltd., Loudi 417009, Hubei, China; 3. Technical Center, Xinyu Iron and Steel Co., Ltd., Xinyu 338001, Jiangxi, China
Abstract:Rapid cooling after rolling has become essential for preparing wear-resistant steel NM400. However,the rapid cooling introduces high-amplitude residual stress in the strip,leading to plate defects and distortions during subsequent processing and use. Therefore,clarifying the phase transformation behavior of NM400 and the effect of the cooling rate on its phase transformation behavior is the key to intervening in the phase transformation behavior and improving the level and distribution of residual stress. Aiming at plate shape difference caused by the two cooling modes adopted in the continuous cooling process,the temperature field and stress-strain field were calculated to reveal the effect of cooling mode on phase transformation plasticity and residual stress of NM400 through thermal simulation experiments,the crack compliance method based on the principle of fracture mechanics and the establishment of ABAQUS finite element simulation model. The results show that the formation of residual stress in the continuous cooling process is divided into three stages,the dominant stage of thermal stress,the dominant stage of surface transformation and the dominant stage of core transformation. The size and direction of phase transformation plastic strain are directly related to the stress loaded at the moment of phase transformation. At the beginning of phase transformation in the core,increasing the cooling rate will increase the volume percent of the phase transformation on the surface. The larger the volume percent is,the larger the tensile stress and the phase transformation plastic strain are,the superposition of which will introduce high-amplitude residual stress in the material. The research results can provide data basis and theoretical basis for the regulation of residual stress in the continuous cooling process of wear-resistant steel NM400.
[1] 高朋,王东城,卓越,等. NM450级低合金高强度耐磨钢淬火残余应力分析[J]. 锻压技术,2019,44(10):157.(GAO Peng,WANG Dong-cheng,ZHUO Yue,et al. Quenching residual stress analysis on NM450 low alloy and high strength wear-resistant steel[J]. Forging and Stamping Technology,2019,44(10):157.) [2] 王国栋. 新一代TMCP技术的发展[J]. 轧钢,2012,29(1):1.(WANG Guo-dong. Development of new generation TMCP technology[J]. Steel Rolling,2012,29(1):1.) [3] 康永林,丁波,陈其安. 我国轧制学科发展现状与趋势分析及展望[J]. 轧钢,2017,34(6):1.(KANG Yong-lin,DING Bo,CHEN Qi-an. Analysis and prospect of development status and trend of rolling discipline in China[J]. Steel Rolling,2017,34(6):1.) [4] 王国栋. 近年我国轧制技术的发展、现状和前景[J]. 轧钢,2017,34(1):1.(WANG Guo-dong. The development,current situation and prospect of rolling technology in China in recent years[J]. Steel Rolling,2017,34(1):1.) [5] Weisz-Patrault D,Koedinger T. Residual stress on the run out table accounting for multiphase transitions and transformation induced plasticity[J]. Applied Mathematical Modelling,2018,60(8):18. [6] 贺连芳,李辉平,赵国群. 淬火过程中温度、组织及应力/应变的有限元模拟[J]. 材料热处理学报,2011,32(1):128. (HE Lian-fang,LI Hui-ping,ZHAO Guo-qun. FEM simulation of temperature,phase-transformation and stress/strain in quenching process[J]. Transactions of Materials and Heat Treatment,2011,32(1):128.) [7] 张然,康进武,黄天佑,等. ZG0Cr13 Ni5Mo不锈钢马氏体相变塑性的实验研究及应用[J]. 清华大学学报(自然科学版),2010,50(8):1183.(ZHANG Ran,KANG Jin-wu,HUANG Tian-you,et al. Experimental study and application of the martensitic transformation plasticity of ZG0Cr13 Ni5Mo stainless steel[J]. Journal of Tsinghua University(Natural Science),2010,50(8):1183.) [8] 邓德安,村川英一,麻宁绪. 相变塑性对低温相变钢焊接接头残余应力计算精度的影响[J]. 焊接学报,2014,35(8):9.(DENG De-an,CUNCHUAN Ying-yi,MA Ning-xu. Effect of transformation plasticity on calculation accuracy of residual stress in welded joints of low temperature transformation steel[J]. Transactions of the China Welding Institution,2014,35(8):9.) [9] 刘玉. 中碳钢淬火应力分布的测定和有限元模拟[D]. 上海:上海交通大学,2017.(LIU Yu. Measurement and Finite Element Simulation of Quenching Stress Distribution of Medium Carbon Steel[D]. Shanghai:Shanghai Jiao Tong University,2017.) [10] 庞博文. 温度应力作用下700L的相变塑性行为及其对残余应力的影响[D]. 武汉:武汉科技大学,2020.(PANG Bo-wen. Transformation Plastic Behaviour and Its Effect on Residual Stress of 700L Under Temperature Stress[D]. Wuhan:Wuhan University of Science and Technology,2020.) [11] 邱增帅. 热轧带钢轧后板形演变规律研究[D]. 北京:北京科技大学,2017.(QIU Zeng-shuai. Research on the Shape Evolution Law of Hot Rolled Strip after Rolling[D]. Beijing:Beijing University of Science and Technology,2017.) [12] 李振垒. 基于超快速冷却的热轧带钢轧后冷却控制系统与策略研究[D]. 沈阳:东北大学,2014.(LI Zhen-lei. Research on Cooling Control System and Strategy of Hot Rolled Strip After Rolling Based on Ultra Fast Cooling[D]. Shenyang:Northeastern University,2014.) [13] DING Wen-hong,LIU Ya-zheng,XIE Jian-xin,et al. Effect of carbide precipitation on the evolution of residual stress during tempering[J]. Metals-Open Access Metallurgy Journal,2019,9(6):709. [14] YANG K,ZHANG Y,HU Z,et al. Optimized welding process of residual stress control of P91 steel considering martensitic transformation[J]. International Journal of Pressure Vessels and Piping,2021(2):104517. [15] Bohemen V,Sietsma J. Effect of composition on kinetics of athermal martensite formation in plain carbon steels[J]. Metal Science Journal,2009,25(8):1009. [16] Lee S J,Tyne C. A kinetics model for martensite transformation in plain carbon and low-alloyed steels[J]. Metallurgical and Materials Transactions A,2012,43(2):422. [17] 秦盛伟,张棒,赵辉辉,等. 18CrNiMo7-6渗碳钢相变塑性系数对残余应力的影响[J]. 表面技术,2021,49(12):138.(QIN Sheng-wei,ZHANG Bang,ZHAO Hui-hui,et al. Effect of transformation plasticity coefficient on residual stress of 18CrNiMo7-6 carburizing steel[J].Surface Technology,2021,49 (12):138.) [18] Johnson G W,Johnson R H. The deformation of metals under small stresses during phase transformation[J]. Proceedings of the Royal Society of London,1965,283(1394):403. [19] Otsuka T,Legrand N. Effect of cooling rate on transformation plasticity of 0.45% carbon steel[J]. ISIJ International,2020,60(4):721. [20] 丁文红,孙力,徐进桥,等. 热轧高强钢残余应力调控技术的研究现状及展望[J]. 轧钢,2022,39(2):1.(DING Wen-hong,SUN Li,XU Jin-qiao,et al. Development and prospect of residual stress control technology for hot rolled high strength steel[J]. Steel Rolling,2022,39(2):1.)