连续退火工艺下退火温度对DP1180钢组织性能的影响  

Effect of annealing temperature in continuous annealing process on microstructure and properties of DP1180 steel

作　　者：张家豪 陈连生 高天洋 徐海卫 韩赟 李红斌 田亚强 ZHANG Jia-hao;CHEN Lian-sheng;GAO Tian-yang;XU Hai-wei;HAN Yun;LI Hong-bin;TIAN Ya-qiang(School of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China;Technology Center,Shougang Jingtang Iron and Steel United Co Ltd,Tangshan 063200,China)

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063210 [2]首钢京唐钢铁联合有限责任公司技术中心,河北唐山063200

出　　处：《材料热处理学报》2023年第3期115-124,共10页Transactions of Materials and Heat Treatment

基　　金：河北省科技厅重点研发计划项目(20311004D);河北省自然科学基金高端钢铁冶金联合基金项目(E2020209124,E2020209127,E2020209040);河北省自然科学基金重点项目(E2022209049)。

摘　　要：采用扫描电镜(SEM)、X射线衍射(XRD)和拉伸实验等研究了退火温度(750、770、790、810、830和850℃)对DP1180钢微观结构演变和力学性能的影响。结果表明:经不同温度退火处理后,DP1180钢显微组织主要由铁素体(F)和马氏体(M)组成。随着退火温度的升高,实验钢中的铁素体和马氏体晶粒尺寸增加,马氏体由岛状变为板条状,抗拉强度和伸长率先增加后降低,而屈服强度则逐渐下降。在试验参数范围内,退火温度为790℃和过时效温度为270℃时,实验钢的综合力学性能最佳,抗拉强度为1255 MPa,伸长率为11.39%,强塑积达到14.29 GPa·%。通过对DP1180钢进行不同变形量的拉伸试验,发现在拉伸过程中微裂纹主要萌生于F/M界面处,随着应变的增加,裂纹在铁素体基体内扩展,裂纹尺寸增加,拉伸后断口形貌既有韧窝区域,又有解理和准解理区域的混合特征区。Effect of annealing temperature(750,770,790,810,830 and 850℃)on microstructure evolution and mechanical properties of DP1180 steel was investigated by means of scanning electron microscopy(SEM),X-ray diffraction(XRD)and tensile test.The results show that the microstructure of the DP1180 steel is mainly composed of ferrite(F)and martensite(M)after annealing at different temperatures.With the increase of annealing temperature,the grain size of ferrite and martensite in the experimental steel increases,the martensite changes from island to strip,the tensile strength and elongation first increase and then decrease,and the yield strength gradually decreases.Within the range of test parameters,when the annealing temperature is 790℃and the over aging temperature is 270℃,the comprehensive mechanical properties of the experimental steel is the best.The tensile strength is 1255 MPa,the elongation is 11.39%,and the product of strength and elongation reaches 14.29 GPa·%.Through the tensile test of the DP1180 steel with different deformations,it is found that the micro-cracks mainly initiate at the F/M interface during the tensile process.With the increase of the strain,the cracks propagate in the ferrite matrix,and the crack size increases.The tensile fracture surface morphology has both dimple area and mixed characteristic area of cleavage and quasi cleavage area.

关 键 词：DP1180钢 连退工艺 退火温度 显微组织 力学性能 

分 类 号：TG142.2[一般工业技术—材料科学与工程]