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汽车拖拉机铸铁活塞环外圆柱表面电镀铬是提高其耐磨性的主要方法。据国内外实践,镀铬后耐磨性提高2～4倍,使拖拉机发动机活塞环平均寿命达4000小时。因此,现在全部第一道气环和大部分油环都采用镀铬。但是这种方法在工艺上存在如下缺点:时间长(3～4小时),生产率低,稳定性差,成本高(约高一倍)。电沉积残渣对周围的大气有危害,产生污水净化的问题。此外,镀铬层已经不能
Automotive Tractors Cast Iron Piston Rings External Cylindrical Surfaces Chrome plating is the primary method of increasing wear resistance. According to domestic and foreign practices, wear resistance after chrome plating increased by 2 to 4 times, so that the average life span of tractor engine piston ring up to 4000 hours. Therefore, all the first gas rings and most oil rings now use chrome plating. But this method has the following shortcomings in the process: a long time (3 to 4 hours), low productivity, poor stability, high cost (about doubled). Electrodeposition residue on the surrounding atmosphere hazardous, resulting in sewage purification problems. In addition, the chrome layer can no longer