Hot-rolled steel plate with tensile strength of 650 MPa and manufacturing method thereof

Abstract

The invention discloses a hot-rolled steel plate with tensile strength of 650 MPa and a manufacturing method thereof, and mainly solves the technical problems of high manufacturing cost, low strengthand low low-temperature impact performance of an existing hot-rolled steel plate for an automobile frame. The hot-rolled steel plate with tensile strength of 650 MPa comprises the following chemical components in percentage by weight: 0.06 to 0.08 percent of C, less than or equal to 0.1 percent of Si, 1.05 to 1.20 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.003percent of S, 0.01 to 0.02 percent of Nb, 0.065 to 0.085 percent of Ti, 0.0015 to 0.0045 percent of Ca, 0.02 to 0.05 percent of Alt, and the balance Fe and inevitable impurities, wherein the contentof the above elements meets the requirement that the carbon equivalent is less than or equal to 0.32. The percentage elongation A of the hot-rolled steel plate after fracture ranges from 18 to 24 percent. The hot-rolled steel plate provided by the invention is mainly used for manufacturing cross beams, longitudinal beams and other structural parts of trucks.

Description

Technical field[0001]The invention relates to a hot-rolled automobile structural steel, in particular to a hot-rolled steel sheet with a tensile strength of 650MPa and a manufacturing method thereof. The hot-rolled steel sheet of the invention is mainly used for manufacturing automobile beams and belongs to the technical field of iron-based alloys.Background technique[0002]Automobile beam steel is mainly used to manufacture the transverse and longitudinal beams of trucks and other structural parts. Automobile beams are formed by cold stamping or roll forming, and are subjected to various impacts, torsion and other complex stresses during the service process. Moreover, China has a vast territory, with an area of ​​around 20°C throughout the year, and some winter temperatures reach -30°C~-40°C The difference in temperature requires the automobile to have good low-temperature impact toughness; therefore, the steel for automobile beams requires conventional high strength, good plasticit...

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Problems solved by technology

[0008] The purpose of the present invention is to provide a hot-rolled steel plate with a tensile strength of 650 MPa and its manufacturing method, which mainly solves the existing technical problems of high manufacturing cost, low strength, and low low-temperature impact performance of the existing hot-rolled steel plate for automobile beams

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