固溶态S31042钢高温塑性波动大的原因分析  

Analysis on Big Fluctuation in Elevated Temperature Ductility of Solution S31042 Steel

作　　者：王敬忠[1,2] 刘正东[1] 程世长[1] 包汉生[1] 

机构地区：[1]钢铁研究总院结构材料研究所,北京100081 [2]西安建筑科技大学冶金学院,陕西西安710055

出　　处：《钢铁》2012年第1期60-64,共5页Iron and Steel

基　　金：国家科技支撑计划资助项目(2007BAE51B02)

摘　　要：为了研究S31042试验用钢短时高温拉伸塑性波动大的原因,采用体视显微镜、金相显微镜、扫描电镜、透射电镜进行了断口形貌和微观组织观察分析,用X射线衍射分析了相应状态试样的萃取粉末。用Thermo-Calc热力学软件进行了相图计算。结果表明:大块簇状的含铌相颗粒分布在晶界和晶内时,固溶态S31042试验钢短时高温(700℃)拉伸塑性较低,伸长率仅28%,而且断裂试样的表面严重龟裂。当钢中的含铌相颗粒细小、独立分布时,短时高温(700℃)拉伸塑性较高,伸长率高达50%,断裂试样的表面没有龟裂。含铌相的形态是固溶态S31042钢塑性波动的原因。因此,改善含铌相颗粒的形态,有益于提高固溶态S31042钢的短时高温拉伸塑性。In order to analyze the reasons which cause big fluctuation in elevated temperature ductility of S31042 steel, the fracture morphologies, surface and mierostructure of specimens were observed by stereomicroscope, met-allographic microscope, scanning electron microscope（SEM）, transmission electron microscope. Extracts powder from specimens at corresponding condition were analyzed by X-ray diffraction. Phase diagram of S31042 steel were calculated using Thermo Calc software. The results show that the big particle of NbCrN in cluster distributing on grain boundaries and in grains is the reason which leads to iow short-term elevated temperature （at 700℃） tensile ductility （elongation only be 28 %） of S31042 steel and serious surface checking. However, the specimen of S31042 steel with fine Nb-precipitation particles distributing dispersedly in grain have relatively high short-term elevated temperature （at 700 ℃ ） tensile ductility （elongation reaching 50%） and no surface checking on the surface of fracture specimens. The major reason which causes fluctuation in elevated temperature ductility of $31042 steel is mor-phologies of Nb-bearing phase. Therefore, improving the morphologies of niobium precipitation particles is benefi- cial to enhance the short term elevated temperature tensile ductility for solution treatment S31042 steel.

关 键 词：S31042钢 高温塑性 表面龟裂 NbCrN相 

分 类 号：TG142.1[一般工业技术—材料科学与工程]