Restamping
Restamping transfers the original material number and heat number onto every cut piece of a certified material. This keeps the link to the test certificate. Without this marking, the leftover piece can't be clearly assigned for welding work.
Physicochemical Mechanism of Action
Re-marking does not change the material. It only transfers the identification (heat number, material designation, test mark) from an approved source piece to cut-off parts. The chemical composition and mechanical properties remain unchanged. The key is the traceable assignment to the original test certificate.
Metallurgical Relevance & Risks in Welding
During welding, the welder needs to know the exact alloy to choose the right filler material, preheat temperature, and post-weld heat treatment. If the marking is missing or transferred incorrectly, there is a risk of mix-up. For example, a plain carbon S235 might be confused with a high-strength S690. The weld cools too fast, martensite forms, and the joint fails brittle. Also, wrong heat treatment or unsuitable filler material can lead to cracks or corrosion damage.
Workshop Practice & Instructions
Only authorized personnel (e.g., welding supervisor) may re-mark. Use a gentle marking method: low-voltage stamping, needle pen, or paint marker. Never hit high-strength, quenched and tempered steels with a sharp center punch – notches can trigger cracks. Transfer the original heat number and test mark unchanged to each remaining piece. Cross-check the data with the mill certificate. Document the transfer in the material log. If in doubt, quarantine the piece and do not use.