调质处理对1000 MPa级水电用钢组织性能的影响  

Effect of quenching and tempering treatment on microstructure and properties of 1000 MPa grade hydropower steel

作　　者：肖桂枝[1] 杨继学 安茹 马金磊 麻衡 XIAO Gui-zhi;YANG Ji-xue;AN Ru;MA Jin-ei;MA Heng(College of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Laiwu Iron and Steel Group Yinshan Section Steel Co Ltd,Jinan 271104,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]莱芜钢铁集团银山型钢有限公司,山东济南271104

出　　处：《材料热处理学报》2024年第9期176-183,191,共9页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51804241)。

摘　　要：利用扫描电镜、透射电镜、拉伸和冲击试验机等研究了不同调质处理工艺对1000 MPa级水电用钢微观组织和力学性能的影响。结果表明:淬火后的实验钢组织呈准等轴状,板条马氏体组织细小。在890~950℃淬火温度范围内,随着淬火温度的升高,马氏体板条束尺寸增加,经过620℃回火后组织转变为回火索氏体,回火过程中碳化物的析出及其与位错的交互作用提高了实验钢的强度。随淬火温度升高,实验钢的屈服强度和抗拉强度增加,伸长率基本保持不变,-60℃冲击吸收能量呈现先缓慢增加后急剧减小的趋势,冲击断裂方式由韧性断裂转变为脆性解理断裂。经920℃×30 min+620℃×60 min调质工艺处理后,实验钢的屈服强度、抗拉强度、伸长率及-60℃冲击吸收能量分别为970 MPa、986 MPa、15%和185 J,其综合力学性能达到最优,满足1000 MPa级水电用钢的性能要求。Effect of different quenching and tempering processes on microstructure and mechanical properties of 1000 MPa grade hydropower steel was studied using scanning electron microscopy,transmission electron microscopy,tensile and impact testing machines.The results show that the microstructure of the experimental steel after quenching is quasi-equiaxed,and the lath martensite is fine.In the quenching temperature range of 890-950℃,with the increase of quenching temperature,the size of martensite packet increases,and the microstructure is transformed into tempered sorbite after tempering at 620℃.The precipitation of carbides and their interaction with dislocation during tempering improve the strength of the experimental steel.As the quenching temperature increases,the yield strength and tensile strength of the experimental steel increase,while the elongation remains basically unchanged,the impact absorbed energy at-60℃shows a trend of first slowly increasing and then sharply decreasing,and the impact fracture mode changes from ductile fracture to brittle cleavage fracture.After quenching at 920℃for 30 min and tempering at 620℃for 60 min,the comprehensive mechanical properties of the experimental steel reach the optimal level,with yield strength,tensile strength,elongation and-60℃impact absorbed energy of 970 MPa,986 MPa,15%and 185 J,respectively,meeting the performance requirements of 1000 MPa grade hydropower steel.

关 键 词：水电用钢 调质处理 微观结构演化 力学性能 强化机理 

分 类 号：TG142.4[一般工业技术—材料科学与工程]