2HGr42 and 2HGr50 are grades of high-strength, low-alloy (HSLA) structural steel plates, primarily specified by the American Petroleum Institute (API) for demanding offshore oil & gas applications, like platforms and FPSOs, known for excellent toughness, weldability, and strength in harsh marine environments, with Grade 50 offering higher strength (around 50 ksi yield) than Grade 42 (around 42 ksi yield), both usually supplied normalized for critical structural components.
Chemical Composition
|
Grade |
C % |
Mn % |
P % |
S% |
Si% |
Nb |
Ti |
Al |
N |
V |
|
2HGr42 |
0.18 |
0.90-1.35 |
0.030 |
0.010 |
0.05-0.40 |
≤ 0.04 |
≤0.02 |
0.02-0.06 |
0.012 |
d |
|
Grade |
C % |
Mn % |
P % |
S% |
Si% |
Nb |
Ti |
Al |
N |
V |
|
2HGr50 |
0.18 |
0.15-1.60 |
0.030 |
0.010 |
0.05-0.40 |
0.01-0.04 |
≤0.02 |
0.02-0.06 |
0.012 |
d |
Mechanical Property
|
Grade |
Yield Strength,kis (Mpa) |
Tensile Strength,kis |
Elongation |
|
2HGr42 |
t≤2.5in 42(289) t≥2.5in 42(289) |
62-82(427-565) |
2in.(50mm) 22 |
|
Grade |
Yield Strength,kis (Mpa) |
Tensile Strength,kis |
Elongation |
|
2HGr50 |
t≤2.5in 50(345) t≥2.5in 47(324) |
70-90(483-620) |
2in.(50mm) 21 |
Key Characteristics
Standard: API Specification 2H.
Type: Normalized, structural steel plate.
Industry: Primarily offshore (oil & gas, marine).
Properties: High strength, good impact toughness, superior weldability, corrosion resistance.
Processing: Controlled rolling or normalizing to achieve properties.
Grade Comparison
2HGr42: Intermediate strength (approx. 42 ksi yield).
2HGr50: Higher strength (approx. 50 ksi yield), more common for critical joints in platforms.
Common Applications
Offshore oil drilling platforms.
Shipbuilding and hull construction.
Platform pipe joints and intersections.
Crane bases and piling in severe conditions (adapted use).
Key Features
Toughness: Essential for resisting impacts from waves, vessels, and dynamic loads, with Charpy V-notch testing performed.
Through-Thickness Properties: Often specified with Z-direction testing (per ASTM A770) for areas under tension.
