DH40
Data verifiedDH40 pairs the 390 MPa strength of the 40-series hull steels with impact toughness certified at −20 °C. It is specified for hull zones and vessel types that see cold water or winter service, where AH40’s 0 °C guarantee is not enough.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.18 |
| Si | ≤0.50 |
| Mn | 0.90–1.60 |
| P | ≤0.035 |
| S | ≤0.035 |
| Note | Nb/V/Ti grain-refining per class rules |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Yield strength | ≥390 MPa |
| Tensile strength | 510–660 MPa |
| Impact | −20 °C, ≥41 J longitudinal (≤50 mm) |
| Density | 7.85 g/cm³ |
Heat treatment
Supplied normalized or TMCP under class survey.
Equivalent grades
| Standard | Designation |
|---|---|
| aisi | A131 DH40 |
| jis | KD40 (near) |
| gb | DH40 (GB/T 712) |
Compare side by side: DH40 vs AH40 · DH40 vs EH40 · DH40 vs DH36
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Cold-service hull structures, LNG/LPG carrier structures, offshore units for temperate-cold fields.
Processing: Same class-survey ordering as AH40 — the D letter is a test-temperature guarantee, not a different steel.
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Ask for a quotationVisit NasteelSource: ASTM A131 / class rules published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.