API 2H Gr42 steel is carburized steel. Carburized steel is usually a low-carbon steel with a carbon content of 0.15%-0.24%. It is a American standard offshore platform structure steel.
API 2HGr42 steel plate executive standard: API Spec 2H-2012
Delivery status of API 2H Gr42 steel plate:
A. Except as permitted in Article B, all steel plates shall be normalized;
B. If approved by the purchaser, grade 50 steel plates with a nominal thickness greater than 2.5in (125mm) can be quenched and tempered.
API 2H Gr42 steel plate heat treatment specification and metallographic structure:
Quenching heating temperature (℃): 815℃-925℃-, oil cooling;
Tempering heating temperature (℃): 595℃-705℃, water cooling, air cooling;
Metallographic structure: tempered martensite.
Low-sulfur steel with improved properties in the thickness direction:
Provide low-grade sulfide-incorporated steel plates through chemical control methods, thereby reducing the possibility of laminar tearing of the steel plates in the joint weld area. The large sulphur content should be 0.006%. The grade suffix xls, x refers to g, n, qt. The low nitrogen content to improve notch toughness under aging-strain conditions, the maximum nitrogen content in melting analysis is 0.009%. Notch toughness requirements at lower temperatures: -67°f (-55°c) drop hammer test ‘unbreak’ or Charpy impact test.
Application range of API 2H Grade 42 steel plate:
API 2H Gr42 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, medium weldability, and normalizing. Good machinability afterwards. Widely used as carburized parts with small cross-sections and high-load quenched and tempered parts with large cross-sections, such as gears, shafts, spindles, worms, sleeves of governors, friction wheels of transmissions.
