奥氏体化温度对M54二次硬化钢组织及力学性能的影响  

Effect of austenitizing temperature on microstructure and mechanical properties of M54 secondary hardening steel

作　　者：张光倩 谢康笛 郭慧琦 周海冲 孙明月[2] 郝露菡 ZHANG Guang-qian;XIE Kang-di;GUO Hui-qi;ZHOU Hai-chong;SUN Ming-yue;HAO Lu-han(National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,Yanshan University,Qinhuangdao 066004,China;Shenyang National Laboratory for Material Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]燕山大学国家冷轧板带装备及工艺工程技术研究中心,河北秦皇岛066004 [2]中国科学院金属研究所沈阳材料科学国家研究中心,辽宁沈阳110016

出　　处：《材料热处理学报》2022年第10期118-127,共10页Transactions of Materials and Heat Treatment

基　　金：河北省自然科学基金-青年科学基金项目(E2021203197);创新研究群体项目(E2021203011)。

摘　　要：采用光学显微镜(OM)、扫描电镜(SEM)、电子背散射衍射(EBSD)和X射线衍射(XRD)等研究了不同温度奥氏体化对M54二次硬化钢微观组织及力学性能的影响。结果表明:当奥氏体化温度较低时,试验钢有较多的未溶(Mo,W)_(6)C碳化物和预处理后的粗大晶粒,使其强度降低,冲击性能恶化。提高奥氏体化温度可减少未溶(Mo,W)_(6)C碳化物的数量,同时奥氏体再结晶使晶粒细化,试验钢的强度和冲击性能快速上升,当奥氏体化温度为1060℃时,试验钢具有优异的强韧性配合,而进一步提高奥氏体化温度到1100℃将导致晶粒迅速粗化进而降低冲击性能。利用EBSD研究了不同温度奥氏体化后试验钢的马氏体亚结构,发现马氏体板条束、板条块具有与奥氏体晶粒相似的变化规律。Effect of austenitizing at different temperatures on microstructure and mechanical properties of M54 secondary hardening steel was studied by means of optical microscope(OM),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD)technique and X-ray diffraction(XRD).The results show that when the austenitizing temperature is low,the experimental steel has more undissolved(Mo,W)_(6)C carbides and coarse grains after pretreatment,which reduces its strength and deteriorates its impact properties.Increasing the austenitizing temperature can reduce the amount of undissolved(Mo,W)_(6)C carbides,and austenite recrystallization can refine the grain,so the strength and impact properties of the experimental steel increase rapidly.When the austenitizing temperature is 1060℃,the experimental steel has excellent strength and toughness,and further increasing the austenitizing temperature to 1100℃will lead to rapid grain coarsening and then reduce the impact properties.The martensite substructure of the experimental steel after austenitizing at different temperatures was studied by EBSD.It is found that the martensite lath bundle and lath block have a change law similar to that of austenite grain.

关 键 词：二次硬化钢 微观组织 力学性能 奥氏体化温度 位错密度 

分 类 号：TG142.3[一般工业技术—材料科学与工程]