The hardness of metal stamping parts is tested by Rockwell hardness tester. Small, complex shape stamping parts can be used to test the plane is very small, can not be tested on the ordinary table Rockwell hardness tester.
Metal stamping parts processing includes blanking, bending, drawing, forming, finishing and other processes. Stamping parts are mainly hot-rolled or cold-rolled (mainly cold-rolled) metal sheet and strip materials, such as carbon steel plate, alloy steel plate, spring steel plate, galvanized plate, tin plate, stainless steel plate, copper and copper alloy plate, aluminum and aluminum alloy plate, etc.
PHP series portable surface Rockwell hardness tester is very suitable for testing the hardness of these stamping parts. Alloy stamping parts are commonly used in metal processing and mechanical manufacturing. Stamping parts processing is the use of dies to separate or form metal strips. Its application range is very wide.
The main purpose of hardness testing of metal stamping materials is to determine whether the annealing degree of purchased metal sheet is suitable for the subsequent stamping processing. Different kinds of stamping parts processing technology require different hardness levels of plates. The aluminum alloy plate used for stamping parts processing can be tested by Wechsler hardness tester. When the material thickness is greater than 13mm, the Babbitt hardness tester can be used. For pure aluminum plate or low hardness aluminum alloy plate, the Babbitt hardness tester should be used.
In the automotive stamping industry, stamping is sometimes called sheet metal forming, but there are some differences. The so-called sheet forming refers to the forming method of plastic processing with sheet metal, thin-walled tube and thin profile as raw materials, which is collectively referred to as sheet forming. At this time, the deformation in the direction of thick plate is generally not considered.
How to check the quality of a stamping part:
1、 Touch test
Wipe the surface of the outer cover with clean gauze. The inspector should wear touch gloves and touch the stamping part surface along the longitudinal direction. This inspection method depends on the experience of the inspector. If necessary, the suspected area can be polished and verified by oilstone, but this method is an effective and rapid inspection method.
2、 Oilstone grinding
1. Firstly, clean the surface of the outer cover with clean gauze, and then polish with oilstone (20 × 20 × 100 mm or larger), and grind the places with arc and hard to reach with relatively small oilstone (for example: 8 × 100 mm semicircular oilstone)
2. The selection of oilstone particle size depends on the surface condition (such as roughness, galvanizing, etc.). It is recommended to use fine-grained oilstone. The grinding direction of oilstone is basically along the longitudinal direction, and it fits the surface of stamping parts very well. Some special places can also be supplemented with horizontal grinding.
3、 Flexible gauze grinding
Wipe the surface of the outer cover with clean gauze. Use flexible sand net to close to the surface of the stamping part and grind it along the longitudinal direction to the whole surface. Any pitting and indentation will be found easily.
4、 Oiling inspection
Wipe the surface of the outer cover with clean gauze. Then use a clean brush to apply oil evenly along the same direction to the entire outer surface of the stamping part. Put the oiled stamping parts under strong light for inspection. It is recommended to erect the stamping parts on the vehicle body. With this method, it is easy to find the tiny pitting, shrinkage pool and ripple on the stamping parts.
5、 Visual inspection
Visual inspection is mainly used to find the appearance abnormality and macro defect of stamping parts.
6、 Inspection with inspection tools
Put the stamping parts into the inspection tool, and inspect the stamping parts according to the operation requirements of the inspection tool instructions.