热输入对纳米析出强化钢激光焊接接头组织及纳米力学性能的影响

发布时间：2018-11-10 08:50

【摘要】：研究了激光焊接热输入对纳米析出强化钢焊接接头熔深、显微组织及纳米力学性能的影响。利用体视显微镜和扫描电子显微镜对焊接接头的熔深、显微组织进行了分析,通过纳米压入实验对激光焊接接头各区域的纳米硬度和弹性模量进行了研究。实验结果表明:随着焊接热输入增加焊缝熔深逐渐增大,两者之间呈一元线性关系;当焊接热输入低于94 J/mm2时,焊缝为全马氏体组织;当焊接热输入超过125 J/mm2时,焊缝中出现贝氏体组织和铁素体组织;且随着热输入的增加,贝氏体和铁素体含量有所增加。随着焊接热输入的增加,焊缝区的纳米硬度逐渐降低,其原因为热输入增大致使贝氏体和铁素体的形成。焊接热输入对焊缝的弹性模量影响不明显,弹性模量在200 GPa左右。
[Abstract]:The effects of laser welding heat input on the penetration depth, microstructure and mechanical properties of the welded joints of nanocrystalline precipitated strengthened steel were studied. The penetration depth and microstructure of the welded joints were analyzed by stereoscopic microscope and scanning electron microscope. The nano-hardness and elastic modulus of laser welded joints were studied by nano-indentation experiment. The experimental results show that the weld penetration increases gradually with the increase of welding heat input, and the relationship between them is linear, and when the welding heat input is less than 94 J/mm2, the weld is a martensite structure. The bainite and ferrite structure appeared in the weld when the welding heat input was more than 125 J/mm2, and the content of bainite and ferrite increased with the increase of heat input. With the increase of welding heat input, the nano-hardness of weld zone decreases gradually, which is due to the formation of bainite and ferrite due to the increase of heat input. The influence of welding heat input on the elastic modulus of weld is not obvious, and the elastic modulus is about 200 GPa.
【作者单位】：安徽工业大学冶金工程学院;苏州大学沙钢钢铁学院;苏州大学机电工程学院激光加工中心;
【基金】：国家自然科学基金资助项目(51305285) 江苏省基础研究计划(自然科学基金)(BK20130315) 江苏省光子制造科学与技术重点实验室开放基金资助项目(GZ201304)
【分类号】：TG407

【共引文献】