Metal stamping parts put exert external force on the plate, strip, pipe and proximate matter through the punch and stamp, so that they produce plastic deformation or separation, thus obtaining the forming processing method of the workpiece of the required shape and size. The workpiece is metal stamping parts.
Metal stamping and forging are plastic processing (or pressure processing), collectively called forging. The blank of metal stamping parts is mainly hot-rolled and cold-rolled steel plate and strip.
1. Heat treatment process: The metal workpiece is heated to an appropriate temperature in a certain medium, and kept at this temperature for a certain time, and then cooled at different speeds.
2. Role: Heat treatment is one of the important processes in the manufacturing of mechanical parts and molds. It can guarantee and improve the performance of the workpiece, such as wear resistance, corrosion resistance and so on.
It can also improve the structure and stress state of the blank, so as to facilitate the cold and hot processing of the precision metal stamping. The role of carburizing treatment is to improve the wear resistance of the surface layer and make the core has a high impact resistance, that is, strong toughness.
3. Classification: Heat treatment of metal can be roughly divided into three types: integral heat treatment, surface heat treatment and chemical heat treatment. Integral heat treatment is the heat treatment of metal of heating the workpiece as a whole and then cooling it at an appropriate speed to change its overall mechanical properties.
Surface heat treatment refers to the heat treatment of metal of heating the surface layer of workpiece to change its surface mechanical properties. Chemical heat treatment is the heat treatment of metal by changing the chemical composition, structure and properties of metal stamping parts surface.
Chemical heat treatment is to heat the workpiece in the medium containing carbon, nitrogen or other alloy elements (gas, liquid, solid). Heat preservation is for a long time, so that the surface of the workpiece will be permeated with carbon, nitrogen, boron and chromium and other elements.
Other heat treatment such as quenching and tempering are sometimes carried out after the infiltration of elements. The main methods of chemical heat treatment are carburizing, nitriding and metal cementing.
From the development and manufacturing experience of all kinds of metal stamping parts, it is known that the drawing stamp is difficult to deal with, because the material will flow, and the problem of stamping rebound is sometimes very troublesome. Different materials will need different compensation processing.
1. Mechanical properties of stamping materials
There are metal stamping parts of different strength on the car, from ordinary plate to high-strength plate. Different plates have different yield strength. The higher the yield strength of the plate is, the more rebound phenomenon is , especially DP series dual phase high-strength steel.
2. Stamping material thickness
During the forming process, the sheet thickness has a great influence on the bending properties, and the rebound phenomenon will gradually decrease with the increase of sheet thickness.
This is because as the thickness of the sheet increases, the material involved in plastic deformation increases, and then the elastic recovery deformation also increases, so the rebound becomes smaller.
With the continuous improvement of the material strength level of thick sheet metal parts, the dimension accuracy of parts caused by rebound is becoming more and more serious. The nature and size of rebound of precision metal stamping are required to be understood in mold design and later process debugging, so as to take corresponding countermeasures and remedy schemes.