【摘要】 采用等离子弧工艺,对槽形表面结构进行强化处理,研究工艺参数对镀层结构和性能的影响,并分析了其界面强化机理。结果表明,等离子弧强化热输入量对镀层质量有明显的影响,热输入量过小难以实现镀层与基体的冶金结合,过大则引起“过加热”,使镀层附近晶粒长大严重,降低镀层附近硬度及强化质量。采用合理的阴线、阳线、倒转侧面制定合理的强化工艺规范,可取得最佳强化效果。等离子束处理镀层界面成分变化分析结果表明。镀层中的Cr与基体Fe发生相互扩散,界面基体组织发生马氏体相变,使镀层与基体之间形成相变硬化层,达到冶金结合,改善了基体微观组织结构。更多还原

【Abstract】 The influence of the parameters on structure and properties of chromium-plating’s grooved surface strengthened by plasma arc had been studied, and the interface strengthening mechanism had been analyzed. The results indicate that the heat input has an obvious effect on the quality of plating. Too little heat input is difficult to achieve the metallurgical bonding between plating and substrate, and too much heat input can cause over-heating which makes serious grain growth near the plating and reduces plating’s hardness and quality. It is possible to obtain the best results by using reasonable rifling rib, hatching rib, and the reverse side process conditions. The EDX results show that Cr and Fe can be mutually diffused in plating’s interface,and substrate near the interface takes place martensite transformation. Phase transformation hardened layer is formed between plating and substrate to achieve metallurgical bonding.更多还原