ML45B

Mass percent, heat analysis, GB/T28906-2025 Table 4. ; 7.1.5 residual Cr/Ni/Cu are each ≤0.20% and Sn≤0.06%; tabulated alloy Cr is not subject to the residual maximum; 7.1.7 product-analysis tolerances follow GB/T222 and must not be directly treated as heat-analysis limits. ; The standard scope for hot-rolled cold-heading wire rod does not replace confirmation of actual supply dimensions and the component manufacturing process; Mechanical properties require separate verification. ; When measuring acid-soluble aluminum, Als0.015–0.055% is used and is retained separately from total aluminum Alt0.020–0.060%; The Al element field must be interpreted with the selected measurement condition. ; Table 4 Note a: A Si lower limit below 0.10% may be negotiated and specified in the contract; do not fill in without agreement. ; Note b: When hardenability and mechanical properties meet requirements and upon mutual agreement, the lower limit of B may be relaxed to 0.0005%; Default 0.0008%. ; Note c: The Ti/N ratio may be agreed upon, but as no uniform value is provided in the original text, it shall not be automatically set or declared as satisfied. ; Note e: Cr may be added by agreement for the first 15 grades, with the addition amount to be confirmed by both parties.