Hot-rolling strip-steel harrow disk suitable for water quenching and manufacture method thereof

Abstract

The invention discloses a hot-rolling strip-steel harrow disk suitable for water quenching and a manufacture method thereof. The harrow disk comprises the following chemical compositions in percent by weight: 0.22%-0.34% of C, 0.1%-0.40% of Si, 1.0%-1.5% of Mn, 0.0070% or less of N, 0.1% or less of Ti, 0.001 %-0.006 % of B, 0.1 % or less of V, 0.020% or less of impurity element P, 0.010% or less of impurity element S, and the balance Fe and unavoidable impurities. The technology comprises a hot-rolling strip steel production technology and a harrow-disk heat treatment technology. The whole technology comprises smelting by a converter, refining by an electric furnace, continuously casting and rolling a slab and performing ultra-rapid cooling, slowly cooling after reeling, performing stamping forming on the harrow disk, quenching, and annealing. The harrow disk is reduced in C and Mn composition content, and thus the steel can be subjected to water quenching, and after water quenching, the textile is fine M. After heat treatment, the hardness reaches 52 HRC or more, the impact energy reaches 18 J or more, the wear resistance and the toughness and plasticity are excellent, the service life is obviously higher than that of a 65Mn-mateiral harrow disk. Also, the water quenching technology is small in environment pollution and accords with environment protection requirement.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and relates to a rake made of hot-rolled strip steel and a manufacturing method thereof, in particular to a hot-rolled strip steel rake suitable for water quenching and a manufacturing method thereof. Background technique [0002] At present, agricultural machinery accessories-rake blades are generally made of 65Mn hot-rolled strip steel after shearing, oil quenching at 850°C-910°C, and tempering at 300°C-400°C. [0003] With the enhancement of our country's awareness of environmental protection, the heat treatment process of oil quenching will be gradually replaced by water quenching, and the harrow blade industry is also actively reforming the quenching process. However, 65Mn is not suitable for water quenching production process due to its high carbon content, high brittleness, and poor plasticity and toughness. [0004] "Research on As-Cast Microstructure and Wear Resistance of MO-Nb Bain...

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Problems solved by technology

However, 65Mn is not suitable for water quenching production process due to its high carbon content, high brittleness and poor ductility.

[0004] "Research on As-Cast Microstructure and Wear Resistance of MO-Nb Bainite Steel" and "New Technology of Squeeze Casting of Ductile Iron Rake" and other papers introduce new material rakes that are directly formed by casting methods, and the casting process is complicated. Low production efficiency

[0005] The patent "CN85100775A-New spring steel 28 manganese silicon boron steel for manufacturing automobile leaf spring" is a steel with high Si content, high production cost, high Si content, and many inclusions in the steel, which affect ductility, plasticity and fatigue performance

[0006] The boron steel in the patent "CN101148737A - A boron-containing steel and its preparation method" is a medium-carbon bar boron steel produced by electric furnace smelting, and cannot be used to make rake blades

[0007] The boron-containing Q345B steel plate in the patent "CN102080179A - A Manufacturing Method of Boron-Containing Structural Steel" has low carbon content. The grain size is refined through controlled rolling technology to improve the strength of the hot-rolled plate, but the steel plate has poor ductility and plasticity, and poor formability. Good, and the patent does not mention the performance of the steel plate after heat treatment. According to the analysis, the carbon content of the steel plate is low, and the hardness after heat treatment is not enough, so it is not suitable for making rake blades

[0008] The steel grades and production processes mentioned in the above documents and inventions are not suitable for the water quenching method to produce rake blades

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