How is the quality of alloy steel pipes determined

1. Composition of alloy steel pipes. Testing for key components such as Cr and C.
2. Compressive strength of alloy steel pipes. Testing the compressive strength of the hardened surface layer.
3. Surface condition of alloy steel pipes. Checking the surface flatness and weld joints for unevenness, ensuring uniform thickness of all hardened surface layers to prevent damage during repairs.
4. Hardness of alloy steel pipes. Observing the surface hardness of the alloy steel pipe, higher hardness indicates better wear resistance and compressive strength.
5. Bending test of alloy steel pipes. Repeated bending test: Clamping one end of the sample and repeatedly bending it in opposite directions on a cylindrical surface of a specified radius to test the metal's repeated bending resistance and reveal its defects.
6. Hammering test of alloy steel pipes. Hammering or forging a sample of specified dimensions. Testing the alloy steel pipe's ability to withstand upsetting plastic deformation at room temperature or high temperature and revealing its defects.
7. Room temperature upsetting test of alloy steel pipes. An upsetting test conducted at room temperature is called a room temperature upsetting test, also known as a cold upsetting test. An upsetting test conducted in a hot state is called a hot upsetting test.
8. Flanging test of alloy steel pipes. This test involves pressing the center of a specified shape into one end of the alloy steel pipe, causing the pipe wall to be uniformly rolled to a specified size, and assessing the pipe wall's ability to withstand plastic deformation.
9. Hydrostatic test of alloy steel pipes. This test involves filling the alloy steel pipe with water or a specified liquid and subjecting it to a specified pressure for a period of time, testing the quality and strength of the alloy steel pipe, and revealing any defects.