Effects of the Annealing Temperature and Prior Microstructures on Cementite Spheroidization during Subcritical Annealing of SCM435 Steel
In this study,an investigation has been carried out for subcritical spheroidization annealing of medium carbon steel(SCM435) used in automotive engine bolt.The effects of temperatures and prior microstructures on cementite spheroidization during subcritical annealing were investigated.For evaluation of the level of spheroidization and cold deformation with different annealing conditions,the cementite area,the aspect ratio and the hardness were recorded.The results indicate that the lamellar cementite broken down into spherical shape gradually with the increases of annealing temperature,while the microstructure mainly consisted of coarse cementite located at ferrite matrix as the temperature exceeds the optimum temperature.In addition,while the coarsening of cementite particles in martensite proceeded with the growth of particles at boundaries with the dissolution of smaller particles within intragranular,the coarsening of cementite particles in pearlite+bainite was found to be more uniform.The results of aspect ratio and hardness suggest that almost fully spheroidized microstructures and the highest performance are obtained after annealing at 720℃,for 5h.
SCM435 steel subcritical annealing time prior microstructures cementite
QIU Musheng HUANG Xueqi TENG Huaxiang JI Cheng
Sheet Metal Research Institute, Shougang Research Institute of Technology,Beijing 100043, China;Beij School of Materials & Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
国际会议
成都
英文
608-611
2016-11-16（万方平台首次上网日期，不代表论文的发表时间）