K418B与1Cr11Ni2W2MoV电子束焊缝组织及性能分析

Microstructure and properties analysis of K418B and 1Cr11Ni2W2MoV electron beam welds

本文研究了K418B高温合金与1Cr11Ni2W2MoV不锈钢的电子束焊接,用扫描电子显微镜、X射线衍射仪、X射线能谱分析、维氏硬度计、万能试验机等对焊接接头显微组织、显微硬度、抗拉强度和断口形貌进行分析。结果表明:用电子束焊接可以实现K418B合金与1Cr11Ni2W2MoV钢的有效连接;焊缝与母材交界处组织为具有一定方向性的树枝晶,焊缝中心为等轴晶,焊缝中心晶粒组织细小,尺寸为5~10μm;焊缝主要由FeCr_(0.29)Ni_(0.16)C_(0.06)固溶体、颗粒状Laves相、针状(Ti、Nb)C碳化物及少量γ'(Ni3Al)相组成;焊缝区的硬度总体低于母材区,平均硬度为280.06HV_(0.3);焊接接头抗拉强度和伸长率分别为716.3MPa和7.63%;焊接接头拉伸断口存在大量解理台阶。

In this paper,the electron beam welding of K418B superalloy and 1Cr11Ni2W2MoV stainless steel was studied.The microstructure,microhardness,tensile strength and fracture morphology of the welded joint were analyzed by means of scanning electron microscope,X-ray diffractometer,X-ray energy spectrum analysis,Vickers hardness tester and universal testing machine.The results show that the effective connection between K418B alloy and 1Cr11Ni2W2MoV steel can be achieved by electron beam welding.The junction structure of weld and base metal is dendritic with certain directivity,and the center of weld is equia axial,with fine grain structure and size of about 5-10μm.The weld is mainly composed of FeCr_(0.29)Ni_(0.16)C_(0.06) solid solution,granular Laves phase,acicular(Ti,Nb)C carbide and a small amount ofγ'(Ni3Al)phase.The hardness of the weld zone is lower than that of the base material zone,and the average hardness is 280.06HV_(0.3).The tensile strength and elongation of welded joints are 716.3 MPa and 7.63%,respectively.There are many cleavage steps in the tensile fracture of welded joint.