热处理对低锰高镍管线钢力学性能的影响  

Effect of Heat Treatment on Mechanical Properties of Low-Manganese and High-Nickel Pipeline Steel

作　　者：陈康[1] 左秀荣[1] 李源[1] 赵鹏翔[1] 王翼鹏 李金玲[1] 

机构地区：[1]郑州大学物理工程学院教育部材料物理重点实验室,河南郑州450052

出　　处：《中北大学学报（自然科学版）》2015年第1期91-96,共6页Journal of North University of China(Natural Science Edition)

摘　　要：采用金相显微镜、扫描电镜观察和力学性能测试研究了650-850℃热处理对低锰高镍TMCP管线钢微观组织及力学性能的影响.结果表明：轧态钢板以针状铁素体组织为主,有良好的强韧性.经650℃高温回火后M/A岛分解并球化,贝氏体发生回复和部分再结晶,大量析出物弥散分布,强度稍有提高,韧性略有降低.经700-800℃双相区加热空冷后的显微组织由铁素体和不规则的M/A或贝氏体组成.700℃热处理抗拉强度升高到778 MPa,但-40℃冲击功依然高达132J,拉伸曲线表现出连续屈服行为.750℃热处理后强度降低,冲击功提高至302J,伸长率提高至22%,具有很好的塑韧性.850℃正火组织强度较低.选择650-750℃的热处理工艺,TMCP钢力学性能得到进一步改善.The effects of heat treatment at 650-850 ℃ on the microstructure and mechanical properties of low-manganese and high-nickel pipeline steel were investigated by metallographic microscope,scanning electron microscopy（SEM）and mechanical property experiment.The results show that the rolling steel has good strength and toughness,due to containing a large amount of acicular ferrite microstructure.After tempering at 650℃,M/A islands decompose and spheroidize,bainite recover and recrystallize,a large number of precipitation occur diffusely,resulting in strength increasing and toughness decreasing slightly.The microstructure consists of ferrite and irregular M/A islands or bainite after dual phase heat treatment and air cooled（700-800 ℃）.After heat treatment at 700 ℃,tensile strength increases to 778 MPa,but-40 ℃impact energy is still as high as 132 J,tensile curve shows continuous yielding behavior.After heat treatment at 750 ℃,strength is decreased,the impact energy is increased to 302 J,elongation rate is increased to 22%,indicating good plasticity and toughness.After normalizing treatment at 850 ℃,the strength of the sample is decreased.So after heat treatment at 650-750 ℃,the mechanical properties of TMCP steel are improved.

关 键 词：管线钢 热处理 微观组织 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]