合金元素钼和冷却速度对中碳非调质钢组织和性能的影响  

Effect of molybdenum and cooling rate on microstructure and properties of medium carbon non-quenched and tempered steel

作　　者：丁忠[1] 王福明[1] 杨占兵[1] 程慧静[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《金属热处理》2008年第10期12-16,共5页Heat Treatment of Metals

基　　金：国家自然基金资助项目(No50574010);教育部博士点基金(No20030008010)

摘　　要：利用膨胀仪研究了含Mo和不含Mo两种中碳非调质钢的连续冷却转变过程,分析了不同冷速下两种钢的组织转变和力学性能,测定了两种钢的室温抗拉强度和冲击功,利用扫描电镜观察了断口形貌。研究结果表明：Mo显著增加中碳非调质钢过冷奥氏体的稳定性,推迟了先共析铁素体和珠光体的转变,有利于转变为较多的针状铁素体。对于含Mo的2号钢,在冷速为1-3℃/s时,可以获得大量的针状铁素体组织。由于添加了0.089%的Mo,使2号钢的空冷组织得到细化,其冲击韧性比1号钢提高了约45%。Continuous cooling transformation for two kinds of medium carbon non-quenched and tempered steels with Mo and without Mo was studied by use of thermal dilatometer. Microstructure and mechanical properties of these two steels at different cooling rates were analyzed. The room temperature tensile strength and the impact energy of the tested steels were measured and the fractography was carried out under SEM. The resHhs show that Mo can obviously improve the stability of undercooled anstenite, postpone the transformation of proeutectoid fcrrite and pearlite and promote the formation of acicular fen-ire. For the No. 2 steel with Mo, when the cooling rates range from 1 ℃/s to 3 ℃/s, the microstructure is composed of a lot of acicular ferrites. Furthermore, with addition of 0. 089wt% Mo, the air cooled microstructure is refined and the toughness is thereby enhanced by about 45 %.

关 键 词：非调质钢 钼 冷却速度 针状铁素体 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]