GB/T 27552-2011

This standard specifies the procedure for conducting microhardness testing on welded joints in metallic materials, covering the preparation of test specimens, measurement methods, and evaluation of hardness profiles across the weld metal, heat-affected zone, and base metal. It is applied in manufacturing industries such as automotive, aerospace, and pressure vessel fabrication to assess the mechanical properties and structural integrity of welds, particularly for quality control and failure analysis. The standard is used during destructive testing of production welds or prototype samples to verify that hardness variations meet design specifications and to detect potential embrittlement or softening issues.