一种Mn-Cr-Mo-La系空冷贝氏体钢轨用钢的试验研究
发布时间：2018-11-22 09:30
【摘要】：利用稀土元素与合金元素的优势互补作用,设计一种低成本高强韧钢轨专用的Mn-Cr-Mo-La系贝氏体钢,通过测定其动态连续冷却转变(CCT)曲线,研究相变行为及组织特征;基于现场钢轨连轧工艺BD1-BD2-CCS进行热连轧模拟试验,采用透射电镜(TEM)观察精细亚结构,分析试验钢的组织细化和强韧化机理。结果表明:由于添加稀土元素可加强Mn、Cr、Mo的淬透性作用,试验钢在冷速范围0.8~2℃/s内可获得大量细小板条贝氏体;其热连轧模拟后的精细组织为板条间带有稳定残余奥氏体膜的无碳化物贝氏体,亚单元宽度细化至39~80nm,块状超细亚单元尺寸为20nm×32nm,板条内发现2~20nm的微细孪晶和高密度位错,使试验钢抗拉强度达1 260 MPa,室温下冲击功达95J,该纳米级贝氏体组织有利于阻碍裂纹扩展,防止贝氏体钢轨轨裂。
[Abstract]:Based on the complementary effect of rare earth elements and alloy elements, a Mn-Cr-Mo-La bainitic steel with low cost and high strength and toughness was designed. The (CCT) curve of dynamic continuous cooling transformation was measured. Study on phase change behavior and microstructure; Based on the field continuous rail rolling process (BD1-BD2-CCS), the hot continuous rolling simulation test was carried out. The fine substructure of the steel was observed by transmission electron microscopy (TEM), and the microstructure refinement and strengthening and toughening mechanism of the steel were analyzed. The results show that due to the addition of rare earth elements to enhance the hardenability of Mn,Cr,Mo, a large number of fine lath bainite can be obtained in the cooling rate range of 0.8 鈩，
本文编号：2348869
[Abstract]:Based on the complementary effect of rare earth elements and alloy elements, a Mn-Cr-Mo-La bainitic steel with low cost and high strength and toughness was designed. The (CCT) curve of dynamic continuous cooling transformation was measured. Study on phase change behavior and microstructure; Based on the field continuous rail rolling process (BD1-BD2-CCS), the hot continuous rolling simulation test was carried out. The fine substructure of the steel was observed by transmission electron microscopy (TEM), and the microstructure refinement and strengthening and toughening mechanism of the steel were analyzed. The results show that due to the addition of rare earth elements to enhance the hardenability of Mn,Cr,Mo, a large number of fine lath bainite can be obtained in the cooling rate range of 0.8 鈩，
本文编号：2348869
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