|
|
|
| SOME PROBLEMS CONCERNING THE APPLICATION OF COLD EXTRUSION |
| The Forging and Stamping Faculty; Shanghai Chiaotung University |
|
Cite this article:
The Forging and Stamping Faculty; Shanghai Chiaotung University. SOME PROBLEMS CONCERNING THE APPLICATION OF COLD EXTRUSION. Acta Metall Sin, 1977, 13(z1): 129-176.
|
|
|
Abstract In China, the application of cold extrusion has been very rapid. Severalkinds of hard metal has been successfully cold-extruded into parts of complicatedshapes. Evidently, the technology of cold extrusion will play an ever-increasingimportant role in our socialist construction. During cold extrusion, the die exerts a high pressure on the material to beextruded and force it to deform whereas the material exerts a reaction on thedie to resist it being deformed. Deformation and resistance against deformationare two contradictory aspects which determine the nature of the process of coldextrusion from beginning to end. However, attention must be drawn to thetransformation of the contradiction. For example, the difference of the flowingrates of metallic particles usually becomes the principal aspect of the contradic-tion when pure aluminium or unsymmetrical steel parts to be slightly deformedare cold-extruded. Workers in China have made contributions to the raising of the allowabledeformation extent, In their actual productions, extrusion pressure may reach,under some circumstances, as high as 300 kg/mm~2, under which, punches canstill be used 50, 000 times and dies 200, 000 times before they are worn out. Based on our experiences gained in actual production, and on the theory ofconcentration of stresses, the principle of "dividing dies before cracking" hasbeen adopted in designing dies, which may considerably prolong their effective life. This paper describes the combined technology of extrusion-upsetting in coldextrusion and the combined extrusion of stainless steel. It seems that the correctchoice of substitute materials suitable to the characteristics of cold extrusioncould make the cold extrusion more promising in its application than ever before.
|
|
|
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
