为进一步探索改善X120管线钢的韧塑性,用X120工业连铸坯在实验室采用TMCP和TMCP后立即感应加热至500和550℃回火工艺进行模拟轧制试验,并检测其力学性能,采用扫描电镜、透射电镜分析了不同工艺下钢的组织及析出物形貌、尺寸及分布,用X射线衍射方法分析了残留奥氏体。结果表明：X120钢组织为下贝氏体、少量针状铁素体以及微量MA。感应加热回火后,板条贝氏体和针状铁素体粗化,小尺寸析出物数量明显增加。这种回火使X120钢韧塑性改善,伸长率达到17.24%,-60℃下冲击功达到232.7 J;不利的是,钢的屈服强度提高和抗拉强度下降导致屈强比更高。性能变化是回火后贝氏体组织粗化、α-Fe基体上大量析出细小弥散碳氮化铌以及残留奥氏体体积分数的变化引起的.
For further improving toughness and plasticity of X120 pipeline steel,simulated rolling experiment was carried out by TMCP and TMCP combined subsequent induction heating tempering at 500 and 550 ℃,respectively.Mechanical properties of the treated samples were tested.Microstructure and precipitates shape,size and distribution of the steel were analysed by SEM and TEM.The retained austenite was detected by XRD.The results show that the microstructure of X120 pipeline steel consists of lower bainite,a small quantity of acicular ferrite and trace retained austenite.The lath lower bainite and acicular ferrite is coarsened and the amount of small size precipitates increase remarkably in the steel after induction heating tempering.The induction temper process improves toughness and plasticity of the X120 steel,with elongation to 17.24% and impact toughness to 232.2 J at-60 ℃.The unfavourable effect is the higher yield ratio of the tempered steel due to the increase of yield strength and the decrease of tensile strength.The mechanical properties variation are caused by lower bainite coarsening,fine and disperse niobium carbonitride precipitation on α-Fe matrix and the change of volume fraction of retained austenite.
参考文献
| [1] | ISHIKAWA Nobuyuki;ENDO Shigeru;KONDO Joe .High Performance UOE Linepipes[J].JFE technical report,2006(7):20-26. |
| [2] | NIU Tao,KANG Yong-lin,GU Hong-wei,YIN Yu-qun,QIAO Ming-liang.Precipitation Behavior and Its Strengthening Effect of X100 Pipeline Steel[J].钢铁研究学报（英文版）,2010(11):73-78. |
| [3] | Tanguya B;Luu T T;Perrinb G et al.Plastic and damage behavior of a high strength X100 pipeline steel experiments and modeling[J].Int JPressure Vessels Piping,2008,85(05):322-335. |
| [4] | 景财年,刘在学,王作成,林晓娟,金成俊.贝氏体等温温度对CMnAl-TRIP钢性能的影响[J].材料热处理学报,2007(04):88-91,96. |
| [5] | 尹云洋,杨王? |
| [6] | Mitsuhiro O;Nobuo K;Joe K .Development of a high-deformability linepipe with resistance to strain-aged hardening by HOP[R].JFE TechnicalReport,2007. |
| [7] | HAYASHI Kenji;NAGAO Akihide;MATSUDA Yutaka .550 and 610 MPa Class High-strength Steel Plates with Excellent Toughness for Tanks and Penstocks Produced Using Carbide Morphology Controlling Technology[J].JFE technical report,2008(11):19-25. |
| [8] | 余伟;谢勇;武会宾 等.X120管线钢的连续冷却相变及显微组织研究[J].材料热处理学报,2012,32(03):62-66. |
| [9] | J.M.GREGG;H.D.H.BHADESHIA .SOLID-STATE NUCLEATION OF ACICULAR FERRITE ON MINERALS ADDED TO MOLTEN STEEL[J].Acta materialia,1997(2):739-748. |
| [10] | 康军艳,余伟,陈银莉.回火工艺对针状铁素体钢组织和性能的影响[J].钢铁,2006(09):65-69. |
| [11] | 武会宾,尚成嘉,赵运堂,杨善武,王学敏,贺信莱.回火对低碳贝氏体钢组织稳定性及力学性能的影响[J].钢铁,2005(03):62-65,82. |
| [12] | 王立军,蔡庆伍,余伟,武会宾,雷爱娣.1500 MPa级低合金超高强钢的微观组织与力学性能[J].金属学报,2010(06):687-694. |
| [13] | 雍岐龙.钢铁材料中的第二相[M].北京:冶金工业出版社,2006 |
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