Weld hardness issue
Thread Content
What should be the appropriate reference value for hardness testing after heat treatment of ordinary welds? Are there any standards that specify this value? Is it necessary to test the hardness of stainless steel after heat treatment as well?
The hardness of the weld generally should not exceed 100 BH of the base material’s hardness; references can be made to DL438 and GB50235. Stainless steel is generally not subjected to heat treatment; even if solutionizing or stabilizing heat treatment is carried out, it is done at the material manufacturing plant, as it cannot be performed on-site.
Stainless steel pipes installed on-site can only be heat-treated on-site
Regarding the heat treatment of welds, different materials have different requirements, as do the hardness values. For details, refer to Table 9-1 \"Basic Requirements for Heat Treatment\" in GBT 20801.4-2006 Code for Pressure Piping – Industrial Piping – Part 4: Fabrication and Installation, Article 9.1 on the scope of heat treatment, and Articles 9.2, 9.3, 9.4, and 9.5 on hardness testing.