激光表面堆焊发展现状及机车零部件修复的应用前景展望

Abstract

激光堆焊可以获得高耐磨性、高耐腐蚀性等优异性能的合金堆焊层，在冶金、机车、船舶等领域展现了诱人的应用前景。与埋弧焊、电渣焊、等离子焊等传统堆焊工艺相比，激光堆焊具有组织较细、堆焊层厚度较大、热变形较小，以及堆焊层与基体呈冶金结合、堆焊层成分及稀释率可控、易实现选区堆焊和工艺自动化等优势。本文对激光堆焊的基本原理及其工业应用几个方面做了简单介绍；阐述了激光加工过程中裂纹、气孔产生的主要原因；为了解决激光加工产生的裂纹、气孔等缺陷，本文对激光与电场、磁场、超声振动场的复合协同发展趋势做了分析预测。在此基础上，本文从裂纹、气孔缺陷的抑制以及避免马氏体组织出现等方面探讨了机车车轮、铁轨激光堆焊修复的可行性及可能面临的挑战，为机车轮芯、轮毂等机车零部件的激光修复工业化应用提供参考。 High hard-wearing, high corrosion resistant and other excellent beam welding alloyed coating can be achieved by laser beam welding, which demonstrates promising applications in the fields of metallurgy, locomotive and boats, etc. Compared with the traditional beam welding technologies, laser beam welding exhibits finer microstructures, thicker welded coating and smaller thermal deformation advantages, as well as good metallurgical bonding between welded coating and substrate, controllable component and dilution of welded coating, selective area welding and automation technology characters. The basic mechanism and technological application of laser beam welding were introduced in this paper, in which the main reasons of crack and porosity of laser processing were clarified. In order to solve the crack and porosity problems of laser processing, the compounded cooperation development trend of laser with electric field, magnetic field and ultrasonic field was analyzed and predicted. Moreover, the possibility and challenge of beam welded repairing for locomotive wheel and rail were analyzed, based on the crack and porosity avoidance and martensite microstructure control, which will provide new ideas for the industrial application of laser repairing of wheel center, wheel flange and other locomotive parts.