铁基合金激光熔覆层磨损性能研究

Study on wear properties of Fe-based alloy coating by laser cladding

为了研究模具钢熔覆层在不同润滑情况下的磨损性能,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,在HT-500磨损试验机进行摩擦磨损试验,对比熔覆层在不同润滑条件下的磨损性能,利用表面形貌仪测量磨痕深度和宽度,并计算磨损率。得到了在载荷为300g和500g时,添加润滑油后与干摩擦相比,摩擦系数分别下降了61%和97.9%,磨损率分别下降了98.7%和99.8%的结果。结果表明,在干摩擦条件下,300g载荷下的磨损性能优于500g载荷时的磨损性能,且500g载荷时发生严重磨损;在相同载荷下,润滑条件下的摩擦系数、磨损率、磨痕宽度都远小于干摩擦条件下的值;润滑条件下,磨损过程比较平稳,没有磨合期。

In order to investigate the tribological performance of laser clad coating on die steel, Fe-based alloy powders were coated on 40Cr steel. The tests were carried out with as laser clad layers as upper samples and GCr15 steel as lower samples by means of HT-500 wear tester. The morphologies of wear scars were observed with optical microscopy, and the wear width and the depth of the samples were measured. With lubricant, when the load was 300g, the friction coefficient and wear rate descended 61%and 98.7% respectively compared with that without lubricant,under the load of 500g, they declined 97.9% and 99.8% respectively. As the tests show, the wear performance with 300g load is better than that with 500g load under dry friction and the laser clad layer is worn out seriously with 500g load. The friction coefficient, wear rate and wear width with lubricant is rather less than that under dry friction with the same load. The wear processes are in steady state under the lubricant condition, without running-in period.