铁素体基球墨铸铁激光表面重熔后的组织与性能

The Microstructure and Property of Ferritic Nodular Cast Iron after Laser Surface Remelting

通过调整激光重熔工艺参数对球墨铸铁进行表面重熔处理 ,获得了白口铸铁层 ,对熔化层的显微组织、力学性能、熔化层 基体界面特性与工艺参数的关系进行了仔细研究 ,结果表明 :快速加热熔化、快速冷却凝固和部分碳被烧损 ,使熔化表面凝固后获得白口铸铁层 ,构成了球墨铸铁与白口铸铁的复合材料 ;激光重熔处理后的白口铸铁层显微组织很细 ,具有高的强度和硬度 ,随着激光束扫描速度的增大 ,显微组织变细 ,硬度增高 ;熔化层的横截面积与激光束扫描速度之间在一定条件下接近双曲线关系。

A ferritic nodular cast iron was surface remelted by different laser remelting processing. A surface layer of white cast iron was obtained. The influence of process parameters on the microstructure and property of interface of the molten layer and substrate were studied carefully. The results indicated that, after the laser remelting, due to the fast heating to melting, the fast quench to solidification and the burnt off of a part of carbon, the white cast iron layer is formed on the surface of the nodular cast iron. Then composite material is formed. The microstructure of the white cast iron layer generated by laser remelting is very fine. And the strength and hardness was very high. With the increase of the scanning speed, the microstructure tends to be fine and the hardness tend to be increased. The relationship between the section area of the molten layer and the scanning speed of the laser beam is close to hyperbolic under certain conditions.