Products FAQ
What is the corrosion resistance of ABS Grade DH32?
ABS Grade DH32 is essentially a carbon-manganese steel and does not form a protective oxide layer like stainless steel. In marine environments, it must be used in conjunction with marine paint (anti-corrosion coating) and sacrificial anodes (cathodic protection). Typically, prior to processing, the steel plates undergo shot blasting or sandblasting and are coated with a primer.
What are the typical delivery conditions (heat treatment processes) for ABS DH32 steel plates?
The mechanical properties of ABS Grade DH32 shipbuilding steel plates are typically achieved through controlled rolling and heat treatment. The most common delivery conditions include:
TMCP: This is an advanced controlled rolling process that yields good low-temperature toughness and weldability.
Normalizing: For thicker gauges, normalising is usually employed to refine the grain structure.
Controlled rolling: Improving production efficiency.
How to verify the quality of ABS DH32 before order?
Buyers should confirm three key documents and inspections:
1. Original classification society mill certificate.
2. Complete MTC mill test report with chemical and mechanical properties.
3. UT ultrasonic inspection and surface quality check to ensure no internal lamination or surface defects.
Is ABS DH32 steel easy to weld?
Yes, ABS DH32 has excellent weldability with low carbon equivalent. It is compatible with SAW, GMAW and SMAW welding processes.
Can ABS DH32 be used for offshore platforms?
Yes, DH32 is suitable for structural components on offshore platforms subject to high loads and operating at ambient temperatures of no less than -20°C. Where structures are exposed to extremely low temperatures or involve critical connection joints (such as TKY joints), it is usually required to use higher-grade EH32 steel or steel plates with Z-direction properties (Z25/Z35) to ensure resistance to laminar tearing.
What is the difference between ABS DH32 and AH32?
Both have the same yield strength; the main difference lies in the impact test temperature. AH32 is tested at 0°C, whilst DH32 is tested at -20°C, making DH32 more suitable for colder or harsher sea conditions.
What is the difference between ABS AH36, DH36, EH36 and FH36?
ABS Grade AH36, DH36, EH36 and FH36 shipbuilding steel plates have the same strength; the key difference lies in the test temperature for low-temperature impact toughness.
| Grade | Impact Test Temperature | Impact Energy, KV2 / J | Suitable for Marine Environments |
|---|---|---|---|
| ABS AH36 | 0°C | 34(Longitudinal), 24(Transverse) | Standard marine environments. |
| ABS DH36 | -20°C | 34(Longitudinal), 24(Transverse) | Cold-water marine environments. |
| ABS EH36 | -40°C | 34(Longitudinal), 24(Transverse) | Polar marine environments with extremely low temperatures. |
| ABS FH36 | -60°C | 34(Longitudinal), 24(Transverse) | Polar/ice regions and ultra-low-temperature deep-sea environments. |
Is ABS AH36 shipbuilding steel plate easy to weld?
Yes, it has excellent weldability and is suitable for manual arc welding, gas shielded arc welding and submerged arc welding.
What are the applications of ABS AH36 steel?
For heavy-load vessels and offshore structures:
Ship hulls: decks, sides, hatch coamings, longitudinal and transverse frames
Offshore platforms: jackets, legs, deck modules
Special-purpose vessels: container ships, bulk carriers, oil tankers, polar vessels, naval vessels.
What precautions should be taken when cutting or storing ABS Grade AH36 marine steel plates?
Storage: Due to the lengthy shipbuilding cycle, the steel plates are prone to rust. They should be stored in a dry, well-drained area and raised on sleepers to prevent contact with soil and standing water. For long-term storage, it is recommended to apply anti-rust oil.
Cutting deformation: Although AH36 is suitable for thermal cutting, due to its microalloying elements, the heat-affected zone is smaller when flame-cutting thin plates (<20 mm). However, when cutting thick plates, care must be taken to control the preheating temperature to prevent microcracks or hardening of the cut edges.
