Read the designation
A, B, D and E are normal-strength hull categories; B, D and E do not mean progressively higher yield strength. AH32, AH36 and AH40 distinguish higher-strength levels. Within one level, the A/D/E/F prefix distinguishes impact-test requirements. Do not confuse ASTM A36 structural steel with AH36 hull steel.
Choose against the approved drawing
Record the structural member, net and gross thickness, design temperature, stress category and classification society. The designer determines the required material category. A colder Charpy test is evidence of a specified test, not a stand-alone minimum service-temperature rating.
Close the purchasing specification
State the rule edition, grade, plate dimensions, delivery condition, inspection documents and supplementary tests. The mill approval must cover the grade, thickness and production route. A distributor describing a plate as marine steel does not establish class acceptance.
Information to record
- Exact product standard and edition; approved drawing or specification revision.
- Grade, dimensions, final condition and heat-to-piece traceability.
- Acceptance test, inspection document and responsible approving party.
Frequently asked questions
Can general structural steel replace class hull plate?
Only after the designer and relevant class society accept the complete substitution. Similar yield strength alone is insufficient.
Sources and reference scope
- Procurement and editorial guidance — Cross-checked against product terminology and the cited material rules
Guidance describes checks to request. It is not a claim of available stock, certificates or completed project engineering. - 钢材产品简介 — Slides 3, 5–6, 15–19
Product forms, units and grade vocabulary; not proof of current stock or class certification. - IACS UR W11 Rev.9 (May 2017) — Sections 1–8; chemistry tables 1–2 and mechanical tables 6–7
Reference values are conditioned on grade, thickness, specimen and project rule. Not ASTM A131 acceptance data. - 中外钢铁牌号速查手册（第4版） — PDF pp. 275–277; printed pp. 264–266, tables 5-4/5-5
GB 712—2011 chemistry is historical reference, not a current contract standard. Table footnotes inspected.