Alloy forged steel and its heat treatment method and use

Abstract

The invention provides an alloy forged steel and its heat treatment method and use. The alloy forged steel comprises: by mass, 0.26 to 0.35% of C, 0.15 to 0.39% of Si, 0.85 to 1.50% of Mn, less than or equal to 0.02% of P, less than or equal to 0.01% of S, 0.80 to 2.00% of Cr, 0.70 to 2.00% of Ni, 0.35 to 1.00% of Mo, and the balance Fe and other elements. Through reasonable proportioning of alloy elements such as Mn, Ni, Cr and Mo, and main chemical components such as C and Si in forged steel materials, through appropriate heat treatment processes, grains are refined; hardenability and heat intensity properties of the alloy forged steel are improved; normal temperature strength and high temperature strength of the alloy forged steel are greatly improved; and excellent comprehensive mechanical properties of the alloy forged steel are obtained.

Description

technical field [0001] The invention relates to an alloy forged steel and a heat treatment method thereof, and also relates to a high-speed train brake disc made of the alloy forged steel. Background technique [0002] The brake disc is an important part of the braking system of the EMU, especially the EMU with a speed of 250Km / h and higher. The quality and performance of the brake disc directly affect the performance indicators of the EMU. The biggest influence on the quality and performance of the brake disc is the various mechanical performance indicators of the alloy forged steel material used in the brake disc. The deficiencies of alloy forged steel materials used for forged steel brake discs of high-speed trains in China mainly include: [0003] (1) The composition matching of the existing alloy forged steel is not reasonable, and the composition is not easy to control during the smelting process, and the comprehensive mechanical properties are not very ideal. For ex...

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Problems solved by technology

[0003] (1) The composition matching of the existing alloy forged steel is not reasonable, and the composition is not easy to control during the smelting process, and the comprehensive mechanical properties are not very ideal

For example, the patent application with the publication number CN1385628A titled "A Material for High-speed Train Brake Disc" (the closest prior art) added chromium, molybdenum , vanadium and other alloy components, but chromium, molybdenum and other alloy components bring about a significant decrease in material plasticity and toughness while increasing the material strength; similarly, although vanadium can refine grains and improve strength, vanadium is easy to oxidize, As a result, its composition is not easy to control during the smelting process, and if it is added too much, it is often easy to disperse unevenly, and it is easy to cause brittleness of the material; in addition, the addition of vanadium will also bring about a decline in the low-temperature impact toughness of the material, affecting the material’s toughness. Temperature adaptability, resulting in reduced braking performance of trains in some cold regions or low temperature seasons

[0004] (2) The heat treatment method of quenching and tempering for the existing alloy forged steel is unreasonable, and the performance of the material cannot be fully further optimized and improved; the resulting brake disc is prone to deformation and cracks, which affects braking Disk life

[0005] (3) Alloy forged steel for forged steel brake discs of high-speed trains in China mainly relies on imports, and the price is expensive

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