High-strength steel sheet with yield strength of 1100MPa and manufacturing method thereof

Abstract

A high-strength steel sheet with yield strength of 1100MPa and a manufacturing method thereof. The high-strength steel sheet comprises, based on the weight percentage, 0.15-0.25% of C, 0.10-0.50% of Si, 0.60-1.20% of Mn, no more than 0.013% of P, no more than 0.003% of S, 0.20-0.55% of Cr, 0.20-0.70% of Mo, 0.60-2% of Ni, 0-0.07% of Nb, 0-0.07% of V, 0.0006-0.0025% of B, 0.01-0.08% of Al, 0.003-0.06% of Ti, no more than 0.00018% of H, no more than 0.0040% of N, no more than 0.0030% of O, and the balance of Fe and inevitable impurities; and the carbon equivalent CEQ is no more than 0.60%. A quenching and a tempering heat treatment are employed to obtain a tempered martensite tissue. The steel provided by the present invention has yield strength no less than 1100MPa, tensile strength no less than 1250MPa, Charpy ballistic work Akv (-40 DEG C) no less than 50J, and good strength and toughness.

Description

technical field [0001] The invention relates to an ultra-high-strength steel plate with good low-temperature toughness, in particular to a high-strength steel plate with a yield strength of 1100 MPa and a manufacturing method thereof. Background technique [0002] High-strength steel plates are used in coal mine machinery such as coal mine hydraulic supports, construction machinery such as crawler cranes, construction cranes and concrete pump trucks, and large marine floating cranes. Mechanical structures usually serve in heavy loads and complex environments, so high-strength steel plates for mechanical structures require high strength and good low-temperature toughness. At present, the high-strength steel plates involved in the European standard EN10025 and the national standard 16270 have a yield strength of up to 960MPa. At present, ultra-large construction machinery, such as large-tonnage crawler cranes and engineering cranes, all need to use steel plates with a yield s...

AI Technical Summary

Problems solved by technology

The larger defect density is the source of micro-cracks, which can form micro-cracks under the action of force. The growth of micro-cracks makes the steel plate break rapidly along the grain boundary. Therefore, the low-temperature impact of high-strength steel plates with martensitic structure low power

Images