Hot rolled steel used for stirrer in automotive stirring tank and production method thereof

Abstract

The invention relates to a hot rolled steel used for a stirrer in an automotive stirring tank with tensile intensity of 750 MPa and a production method thereof. The hot rolled steel comprises the following chemical components by weight: 0.13-0.18% of C, not more than 0.15% of Si, 1.20-1.70% of Mn, 0.016-0.025% of P, not more than 0.008% of S, 0.035-0.070% of Als, 0.07-0.10% of Ti, 0.035-0.055% of Nb and 0.20-0.33% of Cu. The process comprises the following steps: smelting in a converter; treating in an LF furnace (ladle furnace); continuously casting to a blank and heating the cast blank; rolling in a segmental manner; cooling at variable speed and carrying out laminar flow cooling; coiling; and finishing and carrying out an after treatment process. According to the invention, an Rm average value is 780-800 MPa, elongation A is not less than 14%, the surface hardness HV10 reaches 260-300, in comparison with the conventional intensity steel with the same level, the surface hardness is at least improved for 20%, a plate form is easy to control, the surface quality is high, copper is particularly added, and the wear resistance and the anti-corrosion performance of a steel product are greatly improved.

Description

technical field [0001] The invention relates to steel for mechanical engineering and a production method thereof, in particular to a hot-rolled steel with a tensile strength of 750 MPa for an agitator in an automobile mixing tank and a production method thereof. Background technique [0002] The mixing device of the automobile concrete mixing tank is composed of a tank body and a mixer. It is one of the main components of the concrete mixer truck and the core component for the function of the concrete mixer truck. With the development trend of automobile lightweight and the need for weight reduction and energy saving, the tensile strength level of the mixer material is gradually upgraded from 520MPa level to 750MPa level high-strength steel. [0003] At present, the 750MPa grade (or similar grade) hot-rolled steel used in China has the defects of poor wear resistance and corrosion resistance during use. [0004] After a preliminary search, the patent application number is 2...

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Problems solved by technology

[0005] The main purpose of the present invention is to solve the disadvantages of poor wear resistance and corrosion resistance of the currently used hot-rolled steel for the stirrer in the 750MPa grade automobile stirring tank, and to provide a surface hardness HV10 under the premise that the strength performance is satisfied: 260~300, thereby improving the service life of the agitator, the hot-rolled steel for the agitator in the automobile agitating tank and its production method

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