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Non-quenched and tempered steel for engine crankshaft and production method of non-quenched and tempered steel

A non-quenched and tempered steel and production method technology, applied in the field of metallurgy, can solve the problems of increasing the production cost of non-quenched and tempered steel, and achieve the effects of low production raw material cost, low raw material cost, and reduced product processing procedures and production costs

Active Publication Date: 2022-03-15
HUNAN VALIN XIANGTAN IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in order to make the performance of non-quenched and tempered steel products reach or approach the level of quenched and tempered steel, non-quenched and tempered steel usually needs to add certain microalloying elements such as V, Ni, and Mo to play the role of fine grain strengthening and precipitation strengthening. Will increase the production cost of non-quenched and tempered steel

Method used

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  • Non-quenched and tempered steel for engine crankshaft and production method of non-quenched and tempered steel
  • Non-quenched and tempered steel for engine crankshaft and production method of non-quenched and tempered steel
  • Non-quenched and tempered steel for engine crankshaft and production method of non-quenched and tempered steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Non-quenched and tempered steel for engine crankshaft and its production method, the chemical composition of the steel is C=0.38%, Si=0.53%, Mn=1.62%, P=0.010%, S=0.068%, Gr=0.28%, Al =0.018%, N=0.0177%, the rest is Fe and unavoidable impurities; key process steps include:

[0021] (1) Combined blowing converter smelting: molten iron is directly fed into the furnace, the total loading of molten iron and scrap steel is 147t, scrap steel accounts for 32%, the tapping temperature is 1628°C, the end-point active oxygen content is 270ppm, and 350kg aluminum and iron are added for precipitation during tapping For deoxidation, add 300kg of high-alumina refining synthetic slag + 400kg of lime for slag washing, use a sliding plate to stop the slag to control the amount of slag, and ensure that the thickness of the ladle top slag is 38mm.

[0022] (2) Refining: Add 40kg of aluminum particles + 180kg of silicon carbide to the LF furnace for diffusion deoxidation, the total slag am...

Embodiment 2

[0027] Non-quenched and tempered steel for low-cost engine crankshaft and its production method, the composition weight percentage of steel is C=0.37%, Si=0.55%, Mn=1.61%, P=0.011%, S=0.070%, Gr=0.27%, Al=0.021%, N=0.0175%, the rest is Fe and unavoidable impurities; the key process steps are as follows:

[0028] (1) Combined blowing converter smelting: molten iron is directly fed into the furnace, the total amount of molten iron and steel scrap loaded is 150t, steel scrap accounts for 33%, the tapping temperature is 1630°C, the active oxygen content at the end point is 300ppm, and 350kg of aluminum and iron are added for precipitation during tapping For deoxidation, add 300kg of high-alumina refining synthetic slag + 400kg of lime for slag washing, use a sliding plate to stop the slag to control the amount of slag, and ensure that the thickness of the ladle top slag is 35mm.

[0029] (2) Refining: Add 40kg of aluminum grains + 180kg of silicon carbide to the LF furnace for dif...

Embodiment 3

[0034] Non-quenched and tempered steel for low-cost engine crankshaft and its production method, the composition weight percentage of steel is C=0.38%, Si=0.52%, Mn=1.65%, P=0.009%, S=0.069%, Gr=0.27%, Al=0.020%, N=0.0179%, the rest is Fe and unavoidable impurities; the key process steps are as follows:

[0035] (1) Combined blowing converter smelting: molten iron is directly fed into the furnace, the total amount of molten iron and steel scrap loaded is 152t, steel scrap accounts for 35%, the tapping temperature is 1638°C, the active oxygen content at the end point is 320ppm, and 350kg of aluminum and iron are added for precipitation during tapping For deoxidation, add 300kg of high-alumina refining synthetic slag + 400kg of lime for slag washing, and use a sliding plate to stop the slag to control the amount of slag to ensure that the thickness of the ladle top slag is 40mm.

[0036] (2) Refining: Add 40kg of aluminum particles + 180kg of silicon carbide to the LF furnace fo...

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Abstract

The invention discloses non-quenched and tempered steel for an engine crankshaft and a production method of the non-quenched and tempered steel. The steel comprises the following chemical components in percentage by weight: 0.35%-0.40% of C, 0.45%-0.70% of Si, 1.50%-1.70% of Mn, less than or equal to 0.020% of P, 0.055%-0.075% of S, 0.25%-0.35% of Gr, 0.015%-0.035% of Al, 0.015%-0.019% of N and the balance of Fe and inevitable impurities. The process comprises the following steps: (1) smelting in a combined blown converter; (2) refining; (3) vacuum degassing treatment; and (4) continuous casting. According to the non-quenched and tempered steel for the engine crankshaft produced through the method, V, Ni and other micro-alloy elements which are high in price are omitted, Si and Mn alloy elements which are low in price are used as main elements, a small amount of economical S, N, Al and Cr elements are added, the smelting and rolling production technology which is specially designed is matched, and the production cost is reduced. And the produced rolled round steel product is low in inclusion content, uniform in sulfide distribution, high in product performance consistency and capable of meeting the requirements of passenger cars for high quality and high performance, and the grain fineness reaches more than 8 grades.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and relates to a non-quenched and tempered steel for a low-cost engine crankshaft and a production method thereof. Background technique [0002] The conventional heat treatment of steel forgings for traditional engine crankshafts is to cool the forgings to room temperature, then reheat, re-austenize, and then quench + high-temperature tempering. Non-quenched and tempered steel eliminates the process of quenching and tempering heat treatment of forgings, which not only saves energy significantly, but also simplifies the forging treatment process and shortens the furnace production cycle. However, in order to make the performance of non-quenched and tempered steel products reach or approach the level of quenched and tempered steel, non-quenched and tempered steel usually needs to add certain microalloying elements such as V, Ni, and Mo to play the role of fine grain strengthening and precipitatio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/02C22C38/04C22C38/06C22C38/38B22D11/18B22D11/22C21C7/06C21C7/10C22C33/06
CPCC22C38/02C22C38/04C22C38/06C22C38/38C22C38/001C22C33/06C21C7/06C21C7/10C21C7/0056B22D11/18B22D11/225
Inventor 杨庚朝迟云广张群琥郑健刘建杨奇军沈锋
Owner HUNAN VALIN XIANGTAN IRON & STEEL CO LTD