Tribological Phenomenon under Extreme Conditions and Its Application

在本研究中，极端情况是指材料的接触压力高于屈服应力。同样的条件在金属成形过程中也得到了承认。利用整流式摩擦试验机研究了镀锌钢与D2模具钢之间的摩擦特性。主要研究结果如下：(1)GA和GAE钢在拉深过程中，镀锌层被破坏。在这些材料中，镀锌层本身的摩擦特性占主导地位，使其不可能在工件上保持适度的润滑膜。(2)EG镀锌层容易跟随坯体变形，在熨烫过程中不会破坏，因此润滑剂对润滑条件有较大的影响。EG镀锌层的摩擦性能不如GA、GAE和EL，但使用润滑剂可以降低摩擦应力。(3)对于含锌的材料，硫具有极强的添加剂作用，而对于含铁的材料，磷酸盐添加剂具有很好的减摩作用。

In this research the extreme condition means higher contact pressure than yield stress of materials. The same conditions are recognized in metal forming processes. By using the ironing-type friction testing machine frictional characreristics of galvanized steel against die steel D2. The following results are gained.(1)Galvanized layr are destroyed during ironing process in GA and GAE steel. Clacks of galvanized layr makes it impossible to maintain a moderate lubrication film on workpiece, therefore in these materials the original frictional characteristics of layr itself are dominant. The effects of ironing reduction and viscosity of lubricants are very small.(2)The galvanized layr of EG are easy to follow the deformation of bulk and will not destroy during ironing, therefore the lubricant has big effect on lubrication condition. The frictional characteristics of galvanized layr of EG are not so good as GA, GAE and EL, but it is possible to reduce frictional stress by using lubricants.(3)Sulfur has an ability of extreme additives to the materials which has Zn as component, on the other hand phosphate additives has an excellent ability to reduce friction for the materials which has Fe component.