High-strength cast steel for coupler of railway vehicle and manufacturing method thereof

Abstract

The invention discloses high-strength cast steel for a coupler of a railway vehicle and a manufacturing method thereof. The high-strength cast steel comprises the following chemical compositions by weight percentage: 0.22 to 0.28 of C, 0.20 to 0.40 of Si, 1.20 to 1.50 of Mn, 0.40 to 0.60 of Cr, 0.90 to 1.10 of Ni, 0.20 to 0.30 of Mo, 0.030 to 0.080 of Al, less than or equal to 0.30 of Cu, less than or equal to 0.030 of P, less than or equal to 0.030 of S, the balance Fe and unavoidable impurities. The key technology of the manufacturing method is that: the temperature of the tapping liquid steel is controlled to be 1,590 to 1,610 DEG C, the casting temperature is controlled to be 1,560 to 1,580 DEG C, the quenching temperature for the thermal refining of casting is controlled to be 850 to 890 DEG C, and the temper temperature is controlled to be 530 to 590 DEG C. the test indicates that the failure load of the manufactured high-strength cast steel is larger than or equal to 950 MPa, the tensile strength is larger than or equal to 800 MPa, the percentage elongation after fracture is larger than or equal to 10 percent, the reduction of cross section is larger than or equal to 24 percent, and the work done by impact is larger than or equal to 20 J, so the high-strength cast steel can completely meet the requirement on the material of the draft gear for the heavy load transportation of the railway.

Description

technical field [0001] The invention relates to a material for a traction buffer device of a railway vehicle, in particular to a high-strength cast steel for a coupler of a railway vehicle and a manufacturing method of the cast steel. Background technique [0002] The traction buffer device of a railway vehicle is an important part that directly bears the impact of heavy load and speed-up of the vehicle, and the safety of its material selection is very important. At present, the E-grade steel in the AAR-M201 standard specification issued by the American Institute of Railroads is generally used internationally as a high-strength cast steel for wear resistance and low-temperature impact resistance for traction buffer devices. The chemical composition of E-grade steel is regulated by weight percentage. as follows: [0003] Carbon content% Silicon content% Manganese content% Phosphorus content% Sulfur content% Nickel content% 0.22～0.28 ...

AI Technical Summary

Problems solved by technology

[0006] However, with the accelerated development of heavy-duty railway transportation and speed-up, the compression and tensile loads of railway vehicle traction buffers are at least 2.5MN (250t) under normal operating conditions, and may reach 3.0MN (300t) under abnormal operating conditions. ), the mechanical performance requirements such as yield strength and tensile strength of the above-mentioned E-grade steel or its equivalent substitutes have gradually been unable to meet the needs of heavy-duty railway transportation, and railway technicians urgently need to develop a steel with higher yield strength and tensile strength Materials for traction buffers

Images