奥氏体化温度和空冷速率对CFB／M复相钢组织和性能的影响.pdfVIP

奥氏体化温度和空冷速率对CFB／M复相钢组织和性能的影响 苑 晔 ，刘东雨 ，彭建超 ，侯世香 ，刘宗德 ，徐 鸿 ，安江英 ，白秉哲 ，徐雪霞 (1．华北电力大学 电站设备状态监测与控制教育部重点实验室，北京 102206； 2．清华大学先进金属材料教育部重点实验室，北京 100084) 摘要：通过Formaster—F热膨胀仪和Gleeble一1500热／力模拟试验机分别模拟了奥氏体化温度为910 oC和960 oC时 不同直径的无碳化物贝氏体／马氏体(CFB／M)复相钢圆棒在空气中的冷却速率，采用光学显微镜和扫描电镜分 析了奥氏体化温度和冷却速率对CFB／M复相钢显微组织的影响，测定了CFB／M复相钢的硬度和冲击韧度值。 结果表明，在空冷条件下，随圆棒直径增大，CFB／M复相钢的组织由无碳化物贝氏体+马氏体转变成铁素体+无 碳化物贝氏体，硬度随之降低，但冲击功却显著增加。提高奥氏体化温度，可抑制铁素体析出，使CFB／M复相钢 在更大的冷速范围内获得强韧性好的CFB／M复相组织。 关键词：无碳化物贝氏体／马氏体(CFB／M)复相钢；奥氏体化温度；空冷；强韧性 中图分类号：TG142．2；TGll3．25 文献标识码：A 文章编号：0254-6051(2007)12-0061-03 Effect of austenitizing temperature and air cooling rate on microstructure and properties of the CFB／M steel YUAN Ye ，LIU Dong—yu ，PENG Jian—chao ，HOU Shi一)【iang ，LIU Zong—de ，XU Hong ，AN Jiang—ying ， BAI Bing—zhe ．XU Xue—xia (1．Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of Ministry of Education， North China Electric Power University，Beijing 102206； 2．Key Laboratory for Advanced Materials of Ministry of Education，Tsinghua University，Beijing 100084) Abstract：The process of air cooling about CFB／M steel bar with different diameter after austenizing at 9 10 oC and 960 oC was simulated by Formaster-·F thermal dilatometer and Gleeble-·1500 thermal／mechanical simulation machine respec-· tively．The microstructure of the experimental steel was observed by optical microscope and scanning electron micro— scope．The hardness and impact toughness of the experimental steel Was tested．The results show that in the air cooling condition， th the diameter of the steel bar increasing，the microstructure changed from CFB+M mixed microstructure to Ferrite+CFB microstructure．The hardness decreases but the impact toughness increases with the diam eter of the experi— mental steel bar increasing．Th e proeutectiod fer