泥浆泵高铬铸铁材料激光淬火技术及其摩擦磨损性能研究

目的提高高铬铸铁的耐磨性能。方法采用CO_2激光器对高铬铸铁工艺试样进行表面激光淬火,利用MMW-1A型摩擦磨损试验机研究激光淬火后试样在磨粒介质条件下的摩擦学性能,并对试样的表面摩擦系数以及磨损率进行测量与分析。结果淬火后试样表层组织被细化,由表及里可分为淬硬区、热影响过渡区和基体区。与基体相比,淬硬层硬度显著提高,最高硬度出现在次表层,可达1105.7HV。当摩擦磨损试验达到稳定状态时,淬火后的试样表面摩擦系数均比未淬火的低,当淬火带间距为1 mm时摩擦系数最小,其值为0.3左右,而未淬火的试样表面摩擦系数高达0.65。相同磨损时间下,激光淬火试样均比未淬火试样的磨损率小,当淬火带间距为1 mm时,磨损率最小,耐磨性最佳。结论激光淬火技术有效地提高了高铬铸铁材料的耐磨性能,延长了泥浆泵缸套的使用寿命。

Laser Quenching Technology and Friction & Wear Properties of Mud Pump High Chromium Iron Material

The work aims to improve abrasion resistance of high chromium iron. CO2 laser was applied to surface laser-quenchingof high chromium iron sample. Under the condition of abrasive medium, tribological properties of sample subject to laser quenching were studied on MMW-1A-type tester. Surface friction coefficient and wear rate of the sample were measured and analyzed. Surface micro-structure of the samplewas refined by laser quenching, which could be divided into three zones from the surface to the center, namely, quenched zone, heat affected transitionzone and substrate zone. Compared with the substrate, hardness of the quenched layer was enhanced greatly. The maximum hardness up to 1105.7HV was present on the subsurface. When the friction-wear test reached a steady state, friction coefficient of the quenched sample surface was lower than that of the unquenched one. The friction coefficient was about 0.3 (the minimum)at the quenching zoneintervalof 1 mm while that of the unquenched onewas up to 0.65. Provided with the same wear duration, wear rate of the laser quenched sample was lower than that of the unquenched one. Minimum friction coefficient and optimum abrasion resistance were obtained at the quenching zone interval of 1 mm. The laser quenching technology can effectively improve abrasion resistance of high chromium cast iron, and prolong service life of mud pump cylinder.