Heat treatment of pressure equipment
Thread Content
For pressure equipment, it is required that the hardness after heat treatment reach a certain value. So, for the hardness testing after heat treatment, how many test points are required? Mark every weld?
First, what is the type of heat treatment you are using? Thermal treatment for restoring performance? Or post-weld heat treatment? What are the specific requirements regarding hardness? If it is post-weld heat treatment, it should be applied to each welded joint that is to be heat-treated, and this should include the weld seam as well as the heat-affected zones on both sides.
What type of heat treatment is the poster referring to? Why is it necessary to test hardness?
If hardness testing is required after heat treatment, then the main welds, pipe joint welds, and so on must all be tested. The testing locations and quantities, etc., should be specified by the designer.
In the cases I’ve encountered where hardness testing was required after welding, the drawings specified exact requirements regarding the test locations, number of tests to be conducted, testing methods, and the acceptable criteria. I encountered random inspections; I have never faced full inspections.