退火处理对CP780钢组织和拉伸行为的影响  

Effect of annealing on microstructure and tensile behaviors of CP780 steel

作　　者：曹洋洋 李锋[1] 陈立佳[1] 谷雪忠 王斌[2] 张鹏[2] 张哲峰[2] Cao Yangyang;Li Feng;Chen Lijia;Cu Xuezhong;Wang Bin;Zhang Peng;Zhang Zhefeng(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang Liaoning 110870,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang Liaoning 110016,China)

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁沈阳110870 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《金属热处理》2024年第11期104-111,共8页Heat Treatment of Metals

基　　金：吉林省与中国科学院科技合作高技术产业化专项(2021SYHZ0046)。

摘　　要：以CP780钢为研究对象,对其进行预拉伸变形及去应力退火处理,利用金相显微镜(OM)、扫描电镜(SEM)、维氏硬度计、拉伸试验机等手段对不同状态CP780钢的微观组织、硬度、拉伸性能及拉伸断裂形貌进行了系统研究。结果表明,不同状态CP780钢的显微组织主要为贝氏体与铁素体;在400~550℃去应力退火后,试样壁厚中心处出现的贝氏体带状组织是导致拉伸断口出现分层的主要原因;随去应力退火温度的升高,CP780钢因预拉伸变形导致的塑性降低现象得到改善,而强度则是先降低后增大再降低;在600℃去应力退火后,预拉伸变形CP780钢获得了最高的强塑性匹配,强塑积达到16.5 GPa·%。Taking CP780 steel as the research object,the treatments of pre-stretch deformation and stress relief annealing was conducted on it.The microstructures,hardness,tensile properties and tensile fracture morphologies of the CP780 steel in different states were systematically studied by means of the optical microscopy(OM),scanning electron microscope(SEM),Vickers hardness tester and tensile testing machine.The results show that the microstructure of the CP780 steel in different states are mainly the bainite and ferrite.After stress relief annealing at 400-550℃,the bainite banded structure at the center of the specimen wall thickness is the main reason for the delamination of the tensile fracture surface.With the increase of annealing temperature,the plasticity reduction of the CP780 steel due to pre-stretch deformation is improved,and the strength firstly decreases,then increases and then reduces.The pre-stretch deformed CP780 steel stress relief annealed at 600℃obtains the highest strength-plasticity combination,with product of strength and elongation reaching 16.5 GPa·%.

关 键 词：CP780钢 去应力退火 微观组织 拉伸性能 断裂形貌 

分 类 号：TG156.23[金属学及工艺—热处理]