渗硼层对SUS304不锈钢耦合变形的摩擦行为的影响

Friction behavior of SUS304 stainless steel against boride layer under condition of coupling friction with deformation

为了模拟成形过程中板带变形与摩擦的耦合作用,采用自制的耦合变形的摩擦试验装置研究了SUS304亚稳奥氏体不锈钢带分别与淬回火和渗硼处理的DC53冷作模具钢的往复摩擦行为,分析了钢带试样的塑性变形及相变行为并观察了其磨损表面形貌。结果表明,无论是淬回火亦或是渗硼处理的DC53与不锈钢试样配对摩擦,钢带试样的变形量与时间均呈对数关系;载荷增大,摩擦系数减小,而滑动速率对摩擦系数的影响很小,所有试验条件下摩擦系数均随试验进程表现出逐渐降低后趋于稳定的规律。与淬回火钢配对的不锈钢带的磨损机理以粘着磨损为主,与渗硼层明显改善了钢带的粘着磨损趋向,磨损机理以磨粒磨损为主。冷作模具采用渗硼处理可改善不锈钢冲压成形过程中的粘着磨损问题。

In order to simulate the coupling behavior of deformation with sliding friction of metal strip /sheet against die during forming process,a self-made friction tester was used to examine the friction behavior of SUS304 stainless steel against quenched and tempered DC53 steel with and without boronizing treatment under the condition of coupling friction with deformation.Plastic deformation,microstructure evolution and surface morphology of the SUS304 steel strip were analyzed after test.Results show that using quenched and tempered DC53 steel specimens with and without boronizing treatment in the friction pairs,the plastic deformation of stainless steel samples increases with test time in a logarithmic function,the friction coefficient decreases with increasing normal load,and the reciprocating slip speed exhibits little effect on the friction coefficient.The adhesive wear is the main wear mechanism for austenitic stainless steel mating with quenched and tempered DC53 steel.The boride layer on the die remarkably decreases the adhesive tendency of the tribo-pair.Boride treatment for cold-work die is of advantage for decreasing the adhesive of stainless steel during forming.