Steel for microalloying lorry axle and technique for producing the same

Abstract

The invention discloses microalloyed steel used for an axle of a railway freight car, wherein the microalloyed steel contains the following chemical components by weight: 0.50-0.57 percent of C, 0.17-0.40 percent of Si, 0.60-1.00 percent of Mn, 0.20-0.35 percent of Cr, 0.18-0.40 percent of Ni, 0.08-0.18 percent of Mo, 0.02-0.06 percent of Al, 0.020-0.060 percent of Ti, 0.030-0.10 percent of V, less than or equal to 0.010 percent of S, less than or equal to 0.020 percent of P, less than or equal to 0.005 percent of B, less than or equal to 0. 20 percent of Cu, less than or equal to 0.010 percent of Sb, less than or equal to 0.03 percent of Sn, less than or equal to 0.04 percent of As, less than or equal to 0.0015 percent of [O] and less than or equal to 0.0060 percent of [N], and the rest is Fe. The invention has high strength, good plasticity, good low-temperature impact property and good crack-resistance sensitivity.

Description

Technical field: [0001] The invention relates to alloy steel in the iron and steel industry, in particular to the design of high-strength, crack-resistant and high-toughness micro-alloyed steel for axles of railway wagons and its production process. Background technique: [0002] With the sustained and stable development of my country's economy, the railway transportation capacity has become a bottleneck seriously restricting the development of the national economy (the per capita railway mileage in my country is 7cm). For this reason, in 2008, the state proposed a railway construction plan with an investment of 2 trillion yuan. In order to ensure the completion of the construction plan issued by the state, at the same time, learn the lessons of the "5.29" and "7.21" two accidents in 2008, which occurred in "5.29" and "7.21", to curb the failure of axle cracks, completely reverse the passive situation of safe transportation of freight cars, and realize railway transportation...

AI Technical Summary

Problems solved by technology

[0003] At present, ordinary 50 steel is used as the material for domestic axles. After overall heat treatment, ordinary 50 steel has defects such as low strength, low grain size level, and low crack resistance sensitivity. In addition, ordinary 50 steel billets are produced by die-casting technology. , the material composition is seriously segregated, the surface quality is poor, and there are defects such as poor composition uniformity in the isodiametric direction, which is far from meeting the requirements of steel for railway vehicle axles, and there are large safety hazards in use (accidents as mentioned above)