The Research On The Precision Forming Technology Of Sprag By High Speed Steel And The Distribution Of Carbide

This paper presents a new processing technology for W6Mo5Cr4V2high speedsteel (HSS) as the extrusion of sprag. Sprag, the shape of which is complex andasymmetric, is rolling in the sprag clutch for transmitting torque, and in order to havedesirable property in the rugged environment, it must be manufactured by multipleextrusions. Because of the undesirable property of GCr15, the principal will use spragmade by W6Mo5Cr4V2HSS to increase working life. HSS is not suitable fortraditional extrusion due to material characteristics. Therefore, the paper exploratoryresearches the extrusion of HSS sprag, in order to have the innovating at the extrusionand aerospace.First, by studying the material characteristics, the forge ability under hightemperature and the heating processing of the W6Mo5Cr4V2HSS, the technologicalparameters were provided for heat extrusion of HSS sprag. Meanwhile, analyzing thesprag shape, contrasting the lack of wire-electrode cutting, and researching thelubrication, cooling and heating processing, the extrusion process for HSS sprag wassystematic designed.Due to the shape of sprag, the metal would zonal flow at extrusion to makeforging axial bend. The paper analyzed mechanism and regularity of metal zonal flow,and by contrasting diversified improving schemes, presented the eccentric die andopen die to decrease influence form zonal flow to axial bend. Meanwhile, theeccentricities were confirmed by lots of numerical simulations with DEFORM-3D, andthe extrusion technological parameters and die structure were rational designed andadjusted. And then, the feasibility of extrusion processing was verified through largeamount of experiments.At last, the paper pertinent studied the type and influence of the carbide inW6Mo5Cr4V2HSS. And then, the influence for the grain size and homogeneous ofcarbide by extrusion was analyzed and contrasted.