S420G1+QT is a European standard marine structural steel plate, and its implementation standard is EN10225-2009. This type of steel plate is a low-alloy, high-strength steel that is mainly used to hold the welded structure of the offshore frame. S420 indicates the minimum yield strength of the steel plate, and QT indicates the state of heat treatment, i.e., quenching and tempering. 
S420G1+QT steel plate is mainly used in the field of shipbuilding and offshore engineering, and its maximum thickness can reach 100mm. 
Chemical composition analysis of S420G1+QT steel plate
Composition: as, sn, pb, bi, ca, b are residual elements;cr+mo+ni+cu≤0.9；nb+v≤0.09；nb+v+ti≤0.11；alt/n≥2；as≤0.03；sn≤0.02；bi≤0.01；Thickness 15mm, c 015。CEQ = C+Mn 6+(Cr+Mo+V) 5+(Ni+Cu) 15 PCM=C+Si 30+(MN+Cu+Cr) 20+Ni 60+Mo 15+V 10+5BS420G1+QT Mechanical Properties of Steel Plate
Application range of S420G1+QT fixed near-shore frame welded structural steel.
S420G1+QT low-alloy high-strength steel, this product is a welded structural steel for fixed offshore frames, "S" means structural steel, "420" means lower yield strength of steel plate, "QT" means that the delivery state of heat treatment is quenching + tempering (quenching and tempering), the maximum thickness of the steel plate is 100mm, the section steel is 63mm, the section steel delivered in the hot-rolled state is 25mm, the seamless hollow section steel is 40mm, and the high-frequency resistance welded hollow section steel is 20mm, which is widely used in ships and marine engineering. S420G1+QT is the grade in the implementation of the technical standard EN 10225-2009, delivered in a quenched and tempered state, ** ordered rolling, four cutting calculation.
S420G1+QT stock size and cutting, fixed rolling and deep processing services.
Material, Specification, Steel Mill, Tonnage, Remarks.
General specification thickness: 8mm-150mm, width: 1600mm-3900mm, length: 6000mm-14000mm. It can also be rolled according to requirements, and can also be cut according to the drawings according to requirements.
Thickness 8mm-300mm
Width 1500mm-4020mm
Length: 3000mm-18000mm