40Cr钢表面激光熔覆层的磨损性能

 为研究模具钢熔覆层的磨损性能，采用铁基粉在40Cr钢表面进行激光熔覆，以激光熔覆层为上试样,GCr15钢珠为下试样，采用HT－500磨损试验机进行摩擦磨损试验，并与40Cr基体的磨损性能相对比。利用表面形貌仪测量磨痕深度和宽度。研究结果表明：载荷小于250 g时，相同载荷下基体的摩擦系数大。载荷小于300 g时，随磨损时间延长，熔覆层、基体的摩擦系数都随着载荷增加而减小。当载荷为300 g时，基体的摩擦系数在0.563～0.589之间变化，平均值为0.576，且随时间逐渐升高，耐磨性变差；熔覆层的磨擦系数在0.431～0.457之间变化，平均摩擦系数为0.444，磨痕深度和宽度分别是0.65 mm和1.096 μm，且随时间逐渐下降，表现了良好的耐磨性能。当载荷增加到500 g时，平均摩擦系数和磨痕深度比300 g时分别增加了75％和47倍，且摩擦系数逐渐升高，磨损性能下降。

Wear performance of Fe-based alloy coating on the 40Cr steel treated by laser cladding

In order to investigate the tribological performance of laser clad coating about die steel,laser cladding techniques were adopted with Fe alloy powders. Tests were carried out using laser clad layers as upper samples and GCr15 steel as lower samples with HT-500 abrasion tester. The results were compared with 40Cr's. The morphologies of wear scars were observed with optical microscopy. The tests show that the friction coefficient of 40Cr is bigger than the clad coating's with the load less than 250 g. The friction coefficient reduces with load increasing when the load is less than 300 g. The 40Cr's friction coefficient is (0.563～0.589) and increases with time when the load is 300 g. The friction coefficient of laser is (0.431～0.457) and clad layer decreases under the same condition. The performance of laser cladding becomes worse when the load is 500 g with the increase of wear time. The friction coefficient is 75% higher than that of 300 g and the wear depth increases by 47 times at the same time.