激光热处理对1Cr5Mo耐热钢焊接接头拉伸性能的影响

发布时间：2018-07-25 20:07

【摘要】：为了改善1Cr5Mo耐热钢焊接接头拉伸力学性能,利用CO2激光对其进行了表面改性处理,通过拉伸试验考察了激光热处理对拉伸性能的影响。利用扫描电镜观察了焊接接头的断裂形式和断口形貌,并用能谱仪分析了激光热处理前后试样表面化学元素的组成,讨论了残余应力和残余奥氏体对拉伸性能的影响。结果表明,激光热处理前后试样的拉伸断口均为韧性断裂,激光热处理后断裂性能有所提高;激光热处理试样表面产生晶粒细化和残余压应力的强化层,其屈服强度和抗拉强度分别提高了3.4%和13.7%,拉伸性能得到进一步提高;激光热处理试样的残余奥氏体含量有所降低,导致焊接接头的断面收缩率下降了18.61%,而延伸率基本不变,其均匀变形能力有所增强。
[Abstract]:In order to improve the tensile mechanical properties of welded joints of 1Cr5Mo heat-resistant steel, the surface was modified by CO2 laser. The effect of laser heat treatment on tensile properties was investigated by tensile test. The fracture mode and fracture morphology of welded joints were observed by SEM. The composition of chemical elements on the surface of the specimens before and after laser heat treatment was analyzed by energy spectrometer. The effects of residual stress and residual austenite on the tensile properties were discussed. The results show that the tensile fracture is ductile fracture before and after laser heat treatment, and the fracture property is improved after laser heat treatment, and the grain refinement and residual compressive stress are formed on the surface of laser heat treatment specimen. The yield strength and tensile strength of the welded joints were increased by 3.4% and 13.7respectively, and the tensile properties were further improved, and the residual austenite content of the laser treated specimens was decreased, which resulted in the reduction of the cross section shrinkage ratio of the welded joints by 18.61%, while the elongation of the welded joints was basically unchanged. Its uniform deformation ability is enhanced.
【作者单位】：常州大学机械工程学院;
【基金】：江苏省科技支撑计划(工业)(BE2014818) 江苏省普通高校研究生科研创新计划项目(CXLX14-1098)
【分类号】：TG407;TG156.99

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