Axle shaft steel and production method thereof

Abstract

The invention relates to axle shaft steel and a production method thereof, and belongs to the field of alloy steel. The technical problem to be solved is to provide the axle shaft steel with lower production cost. The axle shaft steel comprises the following chemical components in percentage by weight: 0.38 to 0.42 percent of C, 0.26 to 0.32 percent of Si, 0.70 to 0.80 percent of Mn, 0.08 to 0.12 percent of V, 0.015 to 0.02 percent of N, and the balance of Fe and unavoidable impurities. The heat treatment process steps of the axle shaft steel are reduced and the total heat treatment time is shortened, so production energy consumption is greatly reduced and production cost is saved; in addition, compared with those of LZ50 steel, the yield strength, tensile strength and other performance of the axle shaft steel are improved to a certain extent. The invention provides a new choice for the axle shaft steel and has wide application prospect.

Description

technical field [0001] The invention relates to axle steel and a production method thereof, belonging to the field of alloy steel. Background technique [0002] As an important part of a railway vehicle, the axle has been used under repeated or alternating stress conditions for a long time, and the stress situation is complicated. Its quality status is closely related to the safety of railway transportation. In the past, the axle steel mainly used LZ50 steel. The alloy composition of LZ50 steel was: 0.47-0.57% C, 0.17-0.40% Si, 0.60-0.90% Mn, P≤0.020%, S≤0.020%, Al≥0.020%, Cr≤ 0.30%, Ni≤0.30%, Cu≤0.25%, H≤0.00025%, 0≤0.0020%, N≤0.0070%. The yield strength ReL of this axle steel is about 345MPa, the tensile strength Rm is about 6i0MPa, the elongation A is about 20%, the reduction of area Z is about 37%, and the impact energy Aku2 is about 25.J. Since the axle is a large forging, the forged axle has mixed crystals and coarse grains. Therefore, the production of LZ50 steel ne...

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Problems solved by technology

Since the axle is a large forging, the forged axle has mixed crystals and coarse grains. Therefore, the production of LZ50 steel needs to be normalized twice (temperature 810-960°C) + tempered once (tempering temperature is about 550°C), each time of normalizing treatment is about 7 hours, and the holding time of one tempering treatment is about 6 hours, so as to ensure a fine and uniform structure. higher cost

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