上海交通大学学报

上海交通大学学报（自然版）

• 金属学与金属工艺 • 上一篇    下一篇

回火对非调质SG钢组织和性能的影响

汪宏斌，薛厂，彭金明，罗毅，吴晓春   

  1. （上海大学 材料科学与工程学院， 上海 200072）
  • 收稿日期:2009-03-10 修回日期:1900-01-01 出版日期:2010-05-31 发布日期:2010-05-31

Effects of Tempering on Microstructure and Mechanical Properties of Nonquenched and Tempered Bainite SG Steel

WANG Hongbin，XUE Chang，PENG Jinming，LUO Yi，WU Xiaochun   

  1. (School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China)
  • Received:2009-03-10 Revised:1900-01-01 Online:2010-05-31 Published:2010-05-31

摘要： 采用低频力学谱仪、扫描电子显微镜和透射电子显微镜并结合JMatPro软件分析了贝氏体型非调质SG钢在350 °C回火后的组织及强韧化机制，分析其内耗与温度的关系曲线中Snoek峰、SKK峰及其微观形貌，探讨了贝氏体中铁素体的碳原子分布及析出行为、粒状贝氏体中岛状马氏体/奥氏体的分解规律.结果表明：未回火SG钢的Snoek峰强度极低，且贝氏体中铁素体的固溶碳原子含量较低；经350 °C回火2 h后，SG钢的屈服强度最高.这是由于析出强化和位错强化共同作用的结果，其中分解出现的弥散碳化物Cr7C3相起到了主要作用.

关键词: 贝氏体型非调质SG钢, 内耗, 岛状马氏体/奥氏体, 回火, 贝氏体

Abstract: The strengthening and toughening mechanism of nonquenched and tempered bainitic SG steel with tempered at 350 °C was studied by low frequency mechanical spectrum apparatus, scanning electronic microscope, transmission electronic microscope and JMatPro software. By the Snoek and SKK peaks in the internal friction depended on temperature and microstructure analysis, the distribution and precipitation behavior of carbon atoms in the bainitic ferrite and decomposition law of islandlike matensite/austenite were discussed. The results show that the intensity of Snoek in SG steel is very low and bainitic ferrite contains a few solid solution content of carbon atoms; and the yield strength of SG steel with tempered at 350 °C for 2 h is the highest, which is due to the precipitation strengthening from Cr7C3 and dislocation strengthening.

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