Effect of Pulsed Current Treatment on Microstructure and Properties of 304 Stainless Steel Ultra-Thin Strip after Rolling  

作　　者：Qi Liu Wanwan Fan Zhongkai Ren Tao Wang Qingxue Huang 

机构地区：[1]College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China [2]Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China

出　　处：《Chinese Journal of Mechanical Engineering》2024年第6期579-590,共12页中国机械工程学报(英文版)

基　　金：Supported by National Natural Science Foundation of China(Grant Nos.51974196,51804215);China Postdoctoral Science Foundation(Grant No.2020T130463);Shanxi Provincial Key Research and Development Program(Grant No.201903D421047);Shanxi Provincial Science and Technology Major Projects(Grant No.20181102015)。

摘　　要：The annealing process is usually used to heat-treat cold-deformed 304 stainless steel to improve its microstructure and properties to a certain extent;however,it requires a high temperature and a long time.Because the thickness of the ultrathin strip reaches the micrometer level,it has only one or several layers of grains in the thickness direction,and the control of morphology and performance is complex.In this study,pulsed current loading was used to replace traditional annealing for treating ultrathin strips of cold-rolled 304 stainless steel.After loading a 25 W pulsed current treatment for 5 min on the cold-rolled sample,which had a thickness of 0.035 mm and width of 6 mm,complete recrystallization occurred,and the mechanical properties were significantly improved.At this point,the measured temperature was 540°C.When annealing was used to treat the sample with the same temperature and for the same duration,the microstructure was still dominated by deformed crystals,and the mechanical properties were poor.When annealing was used to obtain a microstructure and properties similar to those obtained via 25 W electrical treatment,the required annealing temperature and time were 810°C and 60 min,respectively.Pulsed current can increase the vacancy diffusion flux in the sample,accelerate the atomic movement,reduce the recrystallization activation energy,and make the cold-rolled 304 stainless steel ultrathin strip completely recrystallize at a lower temperature and in a shorter time.As the current power continued to increase,the recrystallized grains grew.When the pulsed current power was increased to 25 W,the recrystallized grains grew negligibly.Both recrystallization and grain growth have power thresholds.This study provides a novel approach for regulating the microstructure and mechanical properties of ultrathin cold-rolled 304 stainless steel strips.

关 键 词：Pulsed current 304 stainless steel ultrathin strip RECRYSTALLIZATION Grain growth 

分 类 号：TG1[金属学及工艺—金属学]