How can the processing quality of metal stamping parts be seen from these aspects?

How can the processing quality of metal stamping parts be seen from these aspects?
In our daily life, metal stamping parts are everywhere. In order to improve the production efficiency and quality of customers, we continue to introduce foreign advanced technology. The quality of metal stamping parts is reflected in these aspects. Analyze from the following points
1. Chemical analysis and metallographic examination
Analyze the content of chemical elements in the material, determine the level and uniformity of material grain size, evaluate the level of free cementite, banded structure and non-metallic inclusion in the material, and check the shrinkage, porosity and other defects of the material.
2. Material inspection
Stamped parts are mainly made of hot-rolled or cold-rolled (based on cold-rolled) sheet metal strips. Stamped parts must have quality certificates to ensure that the materials meet the specified technical requirements. When there is no quality certificate or other reasons, the manufacturer of metal stamping parts can select raw materials for re-inspection as required.
3. Molding performance test
The bending test and cupping test were carried out to determine the work hardening index n and plastic strain ratio r of the material. In addition, the test method of steel sheet formability can be carried out according to the steel sheet formability specification and test method.
4. Hardness test
Rockwell hardness tester is used for hardness test of metal stamping parts. Small and complex shaped stamping parts can be used to test the plane that can not be measured by ordinary Rockwell hardness tester.
5. Other performance requirements
The electromagnetic characteristics of the material and its ability to adhere to the coating and coating were measured.
The technical requirements for processing metal stamping parts are shared here. It should also be noted that the precision and surface condition of hot metal stampings are lower than those of cold metal stampings, but still better than castings and forgings, and the amount of machining is small.