Nb元素对中碳钢热处理组织及力学性能的影响  

Influence of Nb Element on Heat-treatment Microstructures and Mechanical Properties of Medium Carbon Steel

作　　者：杨平[1,2] 

机构地区：[1]重庆大学机电工程系,重庆400044 [2]重庆电子工程职业学院,重庆401331

出　　处：《铸造技术》2015年第8期2007-2008,2017,共3页Foundry Technology

摘　　要：采用光学电镜、扫描电镜及力学性能测试,分析经变形热处理后的两种中碳钢的组织及力学性能变化,揭示Nb对中碳钢性能的影响规律。结果表明,中碳钢中微量Nb元素可细化奥氏体晶粒,晶粒尺寸从原本的34.5μm降低至14.5μm,同时Nb元素还可促进试验钢中铁素体的形成;Nb元素可促进钢铁中含Nb析出物的形成,析出物尺寸为20-50 nm,可抑制晶粒增长,提高中碳钢的屈服强度和低温冲击功。The optical microscopy, SEM and mechanical tests were used to study the influence of Nb element on microstructures and mechanical property of two medium carbon steels after deformation and heat treatment. The results show that Nb in middle carbon steel can refine the austenite grain structure, and the grain size decreases from 34.5 to 14.5μm. Meanwhile, Nb can also promote the formation of ferrite phases. In addition, Nb can also enhance the formation of Nb-rich precipitations, and the grain size of these precipitations are about 20-50 nm, which can inhibit the steel grain growth during heat treatment to increase the yield strength and low temperature impact toughness of medium carbon steel.

关 键 词：组织细化 中碳钢 正火处理 Nb元素 

分 类 号：TG161[金属学及工艺—热处理] TG142.1[金属学及工艺—金属学]