High-strength austenitic stainless steel for economical railway vehicle and manufacturing method thereof

Abstract

The invention discloses high-strength austenitic stainless steel for an economical railway vehicle and a manufacturing method thereof. The high-strength austenitic stainless steel comprises the following chemical components in percentage by mass: 0.03-0.12% of C, 0.4-0.8% of Si, 8.5-14.5% of Mn, 14.0-15.5% of Cr, 1.2-1.8% of Ni, 0.15-0.25% of N, V not more than 0.15%, Ti not more than 0.10%, V+Ti not less than 0.05%, Cu not more than 0.60%, P not more than 0.03%, S not more than 0.01%, and the balance of Fe and inevitable impurities; the room-temperature yield strength is not less than 400 MPa; the tensile strength is not less than 700 MPa; and the ductility is not less than 35%. The stainless steel is applied to the railway vehicle, and can reduce the manufacturing cost under the precondition of satisfying the safety requirement; and the stainless steel is applied to a railway truck, can improve the strength when guaranteeing the economy and the service life, and improves the vehicle lightness level.

Description

technical field [0001] The invention relates to the field of austenitic stainless steel, in particular to an economical high-strength austenitic stainless steel for rail vehicles and a manufacturing method thereof. Background technique [0002] Facing the increasingly severe environmental protection situation and increasingly stringent resource conservation requirements, vigorously developing and improving urban public transportation systems has become one of the measures taken by many countries and regions to deal with energy conservation and consumption reduction. As the carrier of the public transportation system, the lightweight and longevity of urban rail vehicles and public transport vehicles have also become an inevitable development trend. With the introduction of the national medium and long-term railway plan, the requirements for high speed, heavy load and long life of railway freight are further strengthened. At present, the main material of railway freight vehicl...

AI Technical Summary

Problems solved by technology

[0009] At present, the stainless steel used to manufacture urban rail transit vehicles mainly includes European standard 1.4003, Japanese standard SUS301L and Japanese standard SUS304. Among them, the corrosion resistance of 1.4003 stainless steel is stronger than that of carbon steel, and the yield strength under use is basically the same as that of high-strength carbon steel. To meet the needs of further lightweight vehicles; the high strength of SUS301L stainless steel is mainly achieved through cold work hardening, the application parts are limited, and its high chromium and nickel content leads to high cost; the high chromium and nickel content of SUS304 stainless steel, the strength Lower than 1.4003 and SUS301L, it is not an ideal lightweight material for rail vehicles

[0010] At present, railway freight vehicles are mainly made of weathering steel and ferritic stainless steel. The high-strength grade of weathering steel meets the requirements for light weight of the car body in terms of strength, but its corrosion resistance has not improved, and the average thickness of each factory maintenance period is reduced. 1.44mm, it is difficult to meet the 25-year design service life requirements of railway freight vehicles; ferritic stainless steel, especially T4003 stainless steel, which is mainly used at present, has met the manufacturing requirements of railway freight vehicles in terms of economy and corrosion resistance, but its The yield strength is generally 350-400MPa, and there are special requirements for the welding method in the vehicle manufacturing process

[0011] At present, some high-strength austenitic stainless steels at home and abroad such as: Chinese patents CN201110027216.3, CN201210223960.5, CN201410294143.8, CN200810035045.7, CN200710038386.5 and Japanese patent JP2000063998A disclose the chemical composition range of stainless steel, according to its examples It can be known that the room temperature yield strength of these stainless steels in the hot-rolled and annealed state is less than 400MPa, and the final high-strength products need to be cold-rolled with a large amount of deformation to obtain, the product elongation rate is reduced, and the production and processing process is long.

Among them, the Cu content in CN201110027216.3 is relatively high, which is not conducive to the recovery of stainless steel; the rare earth element Ce is added in the Chinese patent CN201410294143.8, the Cr content in the Chinese patent CN200710038386.5 is relatively high, and the Ni and Mo content in the Japanese patent JP2000063998A are relatively high. Both increase the cost of the alloy

[0012] 中国专利CN200810035045.7、CN200710134321.0,日本专利JP2001131713A、JP200063998A、JP4450700B2、JP5618057B2,美国专利US7767037B2、US8900511B2、US6764555B2和欧洲专利EP0481377A2中,均含有较高的合金,如Cr、Ni、Mo等,导致不锈钢 rising cost of

[0013] Chinese patent CN200710039748.2 uses the TRIP effect to obtain stainless steel with a room temperature yield strength of 400MPa or more, but its composition does not contain Ni elements, and it completely relies on Mn and N to adjust the structure. The deformation-induced martensite tends to be serious, which damages the elongation of the steel. , and the corrosion resistance is also weak, which increases the difficulty of production and processing

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