Composition and performance analysis of API 2H Gr50NZ offshore platform alloy steel

API 2H Gr50NZ is steel for offshore platforms, used to make ship hulls, offshore oil production platforms, platform pipe joints and other structural parts. Executive standard: CCS/DNV/ABS/GL/LR/BV/RINA/NK/KR.

API spec 2H-2006 is the standard of American Petroleum Institute, carbon-manganese steel plate for marine structure.

Chemical composition of API 2H Gr50 alloy steel:
Silicon Si: 0.17-0.37%
Manganese Mn: 1.00-1.30%
Chromium Cr: 0.80-1.10%
Sulfur S: ≤0.035%
Phosphorus P: ≤0.035%

API 2H Gr50NZ offshore platform alloy steel tensile properties (transverse sample):
Grade 42 Yield Strength ksi (MPA) Minimum 42 (289), Tensile Strength ksi (MPA) 62-82 (427-565)
50 grade yield strength ksi (MPA) minimum 50 (345), tensile strength ksi (MPA) 70-90 (483-620)
42 grade elongation thickness 50mm-200mm: minimum, %22-18
50 grade elongation thickness 50mm-200mm: minimum, %21-16
Identification: Grade 42 should be identified as API 2H-42, and Grade 50 should be identified as API 2H-50.

The suffix G should be printed on the steel plate for heat treatment, the suffix N for the normalized steel plate, and the suffix QT for the quenched and tempered steel plate. If any of the above elements are added to the steel plate, print C after H in the logo. Steel plates accepted in accordance with the Z thickness direction test procedure shall have a Z printed after the designation.

Delivery status of API 2H Gr50NZ offshore platform steel: hot rolling, controlled rolling, normalizing, quenching and tempering.

Mechanical properties of API 2H Gr50 alloy steel:
Tensile strength σb (MPa): ≥930
Yield strength σs (MPa): ≥735
Elongation δ5 (%): ≥10
Area shrinkage ψ (%): ≥45
Impact energy Akv (J): ≥47) (annealed or high temperature tempering state): ≦187
Sample size: sample blank size is 15mm

API 2H Gr50 offshore platform alloy steel is a carburizing steel with good performance, with high hardenability. After carburizing and quenching, it has a hard and wear-resistant surface and a tough core. It has high low-temperature impact toughness and medium weldability. API 2H Gr50 steel is widely used for carburizing parts with small cross-section and high-load quenching and tempering parts with large cross-section, such as gears, shafts, spindles, worms, sleeves of governors, friction wheels of transmissions, etc.