1. Low-Temperature Toughness Requirements
ASTM A131 Grade D/E has less stringent impact energy criteria than ABS EH40 or GOST R 52927-2015 (Shipbuilding Steel for Ice Navigation).
ASTM A131 D:
Charpy V-notch (CVN) ≥20J at -20°C (for Grade D).
Grade E: ≥20J at -40°C, but lacks requirements below -40°C.
ABS Ice Class EH40:
≥34J at -40°C (mandatory for Arc4–Arc7 vessels).
Additional -60°C testing for extreme polar routes.
GOST Ice Categories (e.g., LU5, L1):
≥50J at -60°C for Arctic-class ships (vs. ASTM's -40°C cap).
Conclusion: ASTM A131 D/E is unsuitable for high ice classes without supplemental testing.
2. Thickness and Plate Quality Restrictions
ABS EH40 and GOST steels support thicker plates (60–100mm) with stricter internal soundness checks.
ASTM A131 D/E:
Max. thickness typically ≤50mm without additional UT (ultrasonic testing).
No mandatory Z-direction (through-thickness) testing, risking lamellar tearing.
ABS EH40:
UT required for all plates >15mm (vs. ASTM's >25mm).
Z35 testing for plates >40mm to prevent delamination.
GOST (e.g., 09G2S):
Guarantees uniform properties up to 120mm for icebreaker hulls.
Implication: ASTM A131 D/E may fail under ice-induced bending stresses in thick sections.
3. Chemical Composition and Microalloying
ABS EH40 and GOST steels optimize alloying for arctic weldability and crack resistance.
ASTM A131 D/E:
Higher carbon (C≤0.23%) and sulfur (S≤0.025%) than ABS/GOST.
No mandatory microalloying (Nb, V, Ti) for grain refinement.
ABS EH40:
Lower carbon (C≤0.18%) and sulfur (S≤0.010%) to reduce cold cracking.
Nb/V microalloying ensures fine-grained toughness.
GOST (e.g., 10KhSND):
Cu-Ni-Cr additions enhance corrosion resistance in ice abrasion zones.
Result: ASTM A131 D/E has poorer weldability and fatigue life in icy conditions.
4. Regulatory and Class Society Recognition
ABS Ice Class and GOST are legally mandated for polar vessels, while ASTM A131 lacks automatic approval.
ABS Ice Class Rules:
Require EH36/EH40 for Arc4–Arc7, excluding ASTM D/E unless supplemental testing is done.
Russian Maritime Register (RS):
GOST steels (e.g., 09G2S, 10KhSND) are compulsory for ice-class ships in Russian waters.
ASTM materials need case-by-case waivers, delaying projects.
IMO Polar Code:
References class society standards (ABS, DNV, RS), not ASTM.
Consequence: Shipowners using ASTM A131 D/E face rejection or retrofitting costs for ice-class certification.
5. Fabrication and Repair Constraints
ABS EH40 and GOST steels are optimized for ice-load welding and crack resistance, unlike ASTM A131 D/E.
Welding Procedures:
ASTM A131 D/E: Preheating ≥100°C for thick plates due to higher CEV (carbon equivalent).
ABS EH40: Lower preheat (75°C) thanks to TMCP processing.
Field Repairs:
GOST steels allow cold repairs (-30°C) with approved electrodes (e.g., OZS-11).
ASTM D/E welds risk hydrogen cracking in polar temperatures.
NDT Requirements:
ABS mandates 100% UT + MT for EH40 ice belts; ASTM A131 has no such rule.
Operational Risk: ASTM A131 D/E increases fabrication delays and failure rates in ice operations.
