Microstructural characteristics and mechanical properties of friction-stir-welded modified 9Cr–1Mo steel
Microstructural characteristics and mechanical properties of friction-stir-welded modified 9Cr–1Mo steel
复制标题
DOI：
10.1007/s10853-019-03346-6
复制
发表时间：
2019-01
影响因子：
4.5
通讯作者：
Shengli Li;Xinqi Yang;Feixiang Wang;Wenshen Tang;Huijun Li
中科院分区：
文献类型：
--
作者：
Shengli Li;Xinqi Yang;Feixiang Wang;Wenshen Tang;Huijun Li
选择改性9Cr-1Mo钢进行搅拌摩擦焊接试验。在300 rpm ~ 50 mm/min和400 rpm ~ 50 mm/min的焊接参数下，成功获得了无缺陷焊接接头。采用扫描电镜、电子背散射衍射和透射电镜观察焊接接头的显微组织。焊缝区（WZ）和高温热影响区的主要组织特征是新淬火马氏体的形成、m23c6碳化物的溶解、晶粒的细化和核平均取向的增加。WZ明显硬化，该区域的最大硬度约为母材（BM）的2倍。焊接接头的极限抗拉强度可达BM的98%。SZ和HAZ的吸收冲击能分别达到BM的77.8%和87.4%。此外，还研究了焊后热处理对焊接接头组织和力学性能的影响。
The modified 9Cr–1Mo steel was selected to conduct friction stir welding experiment. Defect-free welded joints were successfully obtained with the welding parameters of 300 rpm–50 mm/min and 400 rpm–50 mm/min. The microstructures of the welded joint were observed by scanning electron microscopy, electron backscatter diffraction and transmission electron microscope. The main microstructural characteristics of the weld zone (WZ) and the high-temperature heat affected zone are the formation of fresh quenched martensite, dissolution of M23C6carbides, grain refinement and increase in kernel average misorientation. The WZ is significantly hardened, and the maximum hardness of this region is about twice that of the base material (BM). The ultimate tensile strength of the welded joint is up to 98% that of BM. The absorbed impact energies of the SZ and HAZ reach 77.8% and 87.4% that of the BM, respectively. Besides, the influence of post weld heat treatment on the microstructure and mechanical properties of the welded joint was also investigated.