Bainitic steel applied to frog

Abstract

The invention discloses bainitic steel applied to a frog. The chemical compositions of the bainitic steel comprise, by weight, 0.03% to 0.05% of C, 0.3% to 0.5% of Si, 1.8% to 2% of Mn, no more than 0.007% of P, no more than 0.006% of S, no more than 0.0040% of N, 0.25% to 0.45% of Mo, 0.03% to 0.05% of Ti, 0.6% to 0.8% of Cr, 0.9% to 1.1% of Ni, 0.3% to 0.5% of Cu, 0.020% to 0.040% of V, 0.002% to 0.004% of B, 0.01% to 0.02% of Als, and the balance of iron and unavoidable impurities.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a bainite steel for a railway frog core rail. Background technique [0002] With the development of the world economy, especially the rapid development of the domestic economy, the population flow and cargo turnover have risen sharply, which puts forward higher requirements for the railway trains that undertake more than 60% of the transportation tasks. In order to meet the needs of the rapid development of the domestic economy, our country has carried out six major speed increases in recent years. Recently, the country has established a medium and long-term strategic goal and plan for vigorously developing high-speed railways. However, with the increase of train speed, it is necessary It will bring greater inertia and produce greater impact and turbulence. In order to ensure the safety and reliability of high-speed trains, this puts forward higher requirements ...

AI Technical Summary

Problems solved by technology

[0004] ① Unreasonable matching of chemical composition and poor alloying effect. For example, the chemical composition range of commonly used ZGMn13 is: C 1.00-1.45; Mn 11.0-14.00; Si 0.30-1.00, and the rest are a small amount of elements such as Cr, Mo, S, P, etc. The material composed of this composition formula has high C content, poor impact performance, low strength, and poor fatigue resistance, and is not suitable for the working environment of this product.

[0005] ②Due to the complex structure of the full-cast high manganese steel frog, its process determines that the fluidity of molten steel varies greatly during pouring, and the crystallization time difference is relatively large, which will inevitably result in poor microstructure density and coarse grains that cannot be eliminated. Porosity, porosity, inclusions and other casting defects are inevitable, which will inevitably lead to low performance indicators such as strength, plasticity, toughness, impact, wear resistance, fatigue, etc., resulting in low service life

[0006] a. On the main line railway track, it is generally necessary to replace it twice a year. Such frequent replacement affects the normal railway transportation order, which is one of the important reasons for the delay of the train, the suspension of the train, and the traffic congestion.

[0007] b. Due to the low service life, the cost of railway construction and maintenance increases, which seriously affects the economic and social benefits of railway transportation

[0008] ③Because the full-cast high manganese steel frog has not undergone electroslag remelting (refining) and forging, the performance dispersion is relatively large, and there are many uncertain factors in the manufacturing process of the high manganese steel frog, resulting in a relatively large dispersion of performance. Large, this kind of performance dispersion often causes abnormal damage due to local defects, which has an extremely adverse impact on the reliability and safety of railway transportation, and even causes accident hazards

[0009] ④ The low-grade cast-type high-manganese steel frogs are not suitable for the safety, high-speed, and heavy-duty needs of China's railway transportation: from the beginning of my country's railway transportation to the present, high-manganese steel frogs have only changed in composition and structural form, while The as-cast structure has not changed all the time. This kind of structure causes its product grade to remain in the original state, which cannot meet the current needs of my country's railway transportation safety, high speed, and heavy load.