800 MPa-level high-strength-tenacity steel plate used for engineering machine in extremely cold environment and manufacturing method for 800 MPa-level high-strength-tenacity steel plate

Abstract

The invention provides an 800 MPa-level high-strength-tenacity steel plate used for an engineering machine in an extremely cold environment and a manufacturing method for the 800 MPa-level high-strength-tenacity steel plate. The steel plate and the manufacturing method are suitable for manufacturing of mechanical components with high requirements for the strength and low-temperature tenacity of the steel plate. The 800 MPa-level high-strength-tenacity steel plate comprises the chemical components including, by weight percentage, 0.12% to 0.17% of C, 0.15% to 0.40% of Si, 0.90% to 1.50% of Mn, smaller than or equal to 0.008% of P, smaller than or equal to 0.003% of S, 0.015% to 0.060% of Al, 0.010% to 0.030% of Ti, 0.030% to 0.070% of Nb, 0.12% to 0.60% of Ni, 0.10% to 0.50% of Cr, 0.20% to 0.50% of Mo, 0.0015% to 0.0030% of B and the balance Fe and inevitable impurities. The steel plate is a high-strength steel plate with the tensile strength at an 800 MPa level, the relatively low alloy adding amount is adopted, the carbon equivalent is low, the welding performance is good, the grain of the steel plate is fine and small, the structure is dense, the inner quality is good, the performance is stable and even, the steel plate especially has the particularly excellent low-temperature tenacity, the Charpy impact absorbing energy at the test temperature of -60 DEG C is kept at a high level, and the steel plate can be used for manufacturing of the engineering machine in the extremely cold environment and is safe and reliable.

Description

technical field [0001] The invention belongs to the field of metal material manufacturing, and relates to a high-strength steel plate with a tensile strength of 800 MPa and a manufacturing method thereof. The high-strength steel plate has excellent low-temperature toughness, and the Charpy impact absorption energy at a test temperature of -60°C maintains a relatively high level, and can be used Manufacture of construction machinery used in extremely cold regions. Background technique [0002] Worldwide, in order to meet the growing demand for energy for economic development, the pace of resource and energy development in arctic regions is also expanding. Since the new construction is located in a high-latitude area, extreme weather occurs frequently, and the temperature in winter can reach -40°C or even lower, which puts forward higher requirements for the construction reliability of construction machinery in extremely cold areas. In the early stage, the design of domestic ...

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Problems solved by technology

[0006] The object of the present invention is to solve the above-mentioned existing problems and provide an 800MPa-grade high-strength toughness steel plate for construction machinery and its manufacturing method that is suitable for extremely cold regions, and solve the problems of limited specifications, poor weldability, and low-temperature toughness of traditional quenched and tempered high-strength structural steels. The problem of not being able to adapt to the extreme cold environment

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