The Mill Test Certificate (MTC) or Certificate of Compliance is the legal and technical passport for ASTM A515 Gr.65 steel plate. For engineers, inspectors, and buyers, understanding and verifying its key contents is a critical quality control step to ensure material integrity for pressure vessel fabrication.
Critical Verification Items in the MTC
A valid MTC for A515 Gr.65 must clearly state the following mandatory information:
Material Designation: Full specification (e.g., ASTM A515/A515M Grade 65) and, if applicable, the ASME Code designation (SA-515/SA-515M Gr.65).
Heat/Cast Number: The unique identifier for the molten steel batch, enabling full traceability from melt to plate.
Chemical Composition (Heat & Product Analysis): Must confirm compliance with ASTM limits for Carbon, Manganese, Silicon, Phosphorus, and Sulfur.
Mechanical Properties: Verified test results for Tensile Strength, Yield Strength, and Elongation, meeting the specified minimums.
Heat Treatment Condition: Must state the plate was supplied in the Normalized or Stress-Relieved condition, as required by the specification.
Test Reports Reference: References to the actual test reports (e.g., tensile test, chemical analysis reports) that support the declared values.
Manufacturer's Name & Stamp: The official stamp or signature of the steel mill, confirming the document's authenticity.
Compliance Statement: A clear declaration that the material complies with the ASTM A515 standard.
Additional Due Diligence for Critical Service
For high-integrity applications (e.g., boilers, high-pressure vessels), also verify:
Supplementary Test Data: Reports for Ultrasonic Testing (UT), Impact Testing, or other tests specified in your purchase order.
Dimensional Verification: Confirmation that plate dimensions and tolerances meet the ordered requirements.
