ASTM A203 Grade D is a nickel-alloy pressure vessel steel designed for welded equipment operating in medium-to-low temperature environments. With its 3.5% Ni composition, A203 Gr.D provides enhanced toughness, stable weldability, and dependable strength retention under sub-zero service conditions. It is widely used in cryogenic vessels, LNG storage systems, gas separation units, and other pressure equipment requiring reliable low-temperature performance and long-term structural stability.
 
Chemical Composition

C	Mn	P	S	Si	Ni
≤0.17	0.40–0.70	≤0.025	≤ 0.025	0.15–0.30	3.25–3.75

 
Mechanical Properties

Property	Yield Strength	Tensile Strength	Elongation	Impact Energy
Requirement	≥ 250 MPa	485–620MPa	≥ 22%	Excellent low-temperature performance (per ASTM A203 requirements)

 
Dimensions

Thickness	3–150 mm
Width	1220–4200 mm
Length	5000–18000 mm
Supports custom cutting and shaping.

 
Stock & Processing
Regular stock for A203 Grade D
Cutting, drilling, welding, bending, machining
Custom dimensions available
Fast delivery for project orders
Global supply capability
 
Applications
LNG storage tanks
Cryogenic pressure vessels
Gas separation and refrigeration units
Low-temperature reactors
Welded components requiring nickel-alloy toughness