70Mn激光表面重熔工艺参数研究

Study on the Laser Surface Remelting Process Parameters of 70Mn

为实现70Mn表面的小直径激光重熔强化,以重熔区深度0.30mm、宽度0.80mm为目标,研究了在不同扫描速率和不同激光功率下的70Mn钢表面“条纹型”重熔单元制备工艺,确定了适用于2mm厚70Mn钢的激光表面重熔工艺参数组合。结果表明:大气环境下,重熔得到的条纹表面较氩气保护环境下的条纹表面粗糙,条纹两侧氧化严重并伴有严重的凸起;在氩气保护环境下,激光扫描速率10mm/s、激光功率400W时,试样可以获得目标重熔区深度(337.3μm)和宽度(817.2μm)。这为滚动轴承滚道等表面的激光重熔强化提供了重要参考。

In order to realize the small diameter laser remelting of 70Mn steel,the preparation process of‘stripe'remelting unit on the surface of 70Mn steel at different scanning rate and laser power was studied with the aim of remelting zone depth of0.30mm and width of 0.80mm,and the combination of process parameters suitable for 2mm thick 70Mn steel was determined.The results show that the surface of the fringes obtained by remelting in the atmosphere is rougher than that in the argon environment,and the two sides of the fringes are oxidized seriously with serious bulges;in the argon environment,when the laser scanning rate is 10mm/s and the laser power is 400W,the target remelting zone depth(337.3μm)and width(817.2μm)can be obtained.This provides an important reference for laser remelting and strengthening of rolling bearing raceway and other surfaces.