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Method for preparing novel nodular cast iron railway turnout accessory

A technology for ductile iron and railways, applied in casting molding equipment, casting molds, cores, etc., can solve the problems of poor antifreeze and fracture resistance, and achieve the effects of avoiding molten iron splashing, improving corrosion resistance, and reducing slag inclusions

Active Publication Date: 2020-08-18
JIANGSU JINYULONG RAILWAY EQUIP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Existing railway turnout fittings are made of nodular cast iron to make them have excellent properties such as high hardness and good toughness. However, ordinary nodular cast iron railway turnout fittings have the problem of poor antifreeze and fracture resistance, so they cannot be used in high cold Therefore, it is necessary to improve its preparation method to obtain turnout accessories with high low temperature impact resistance

Method used

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  • Method for preparing novel nodular cast iron railway turnout accessory

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preparation example Construction

[0023] The invention provides a method for preparing a novel ductile iron railway turnout fitting, wherein the mass percentages of elements in the novel ductile iron railway turnout fitting are: carbon 4.3%-4.7%, silicon 2.3%-2.5%, nickel 0.5% -0.7%, aluminum 0.01%-0.06%, magnesium 0.02%-0.03%, manganese≤0.2%, phosphorus≤0.02%, sulfur≤0.01%, and the balance is iron.

[0024] Among them, the carbon equivalent is controlled at 4.3%-4.7%, and its content is increased compared with the conventional preparation method. By properly increasing the carbon equivalent, the fluidity of molten iron can be increased, which is beneficial to casting and feeding, and it is also useful to use molten iron Ferrite is formed, and at the same time, it is beneficial to the decomposition of cementite and pearlite in the matrix structure during the annealing process, so as to obtain more ferrite matrix structure, thereby improving the low-temperature impact resistance and plasticity of the new ductile...

Embodiment 1

[0035] A method for preparing a novel ductile iron railway turnout fitting provided by the present invention, wherein the mass percentages of elements in the novel ductile iron railway turnout fitting are: 4.3% carbon, 2.3% silicon, 0.5% nickel, 0.01% aluminum, Magnesium 0.02%, manganese ≤ 0.2%, phosphorus ≤ 0.02%, sulfur ≤ 0.01%, the balance is iron;

[0036] Its preparation method specifically comprises the following steps:

[0037] Step 1: Add high-quality pig iron, scrap steel containing carbon steel components, nickel ingots and aluminum ingots into the intermediate frequency induction furnace. During the smelting process, the temperature of the molten iron is kept at 1450°C to obtain molten iron with qualified chemical composition;

[0038] Step 2: Add an inoculant of 0.3% of the total amount of molten iron into the spheroidizing ladle with slag collecting bags with filters installed on the upper end and the bottom, and use an intrusive spray gun to spray blunt into the sp...

Embodiment 2

[0045] The invention provides a method for preparing a novel ductile iron railway turnout fitting, wherein the mass percentages of elements in the novel ductile iron railway turnout fitting are: 4.4% carbon, 2.35% silicon, 0.55% nickel, 0.025% aluminum, Magnesium 0.023%, manganese ≤ 0.2%, phosphorus ≤ 0.02%, sulfur ≤ 0.01%, the balance is iron;

[0046] Its preparation method specifically comprises the following steps:

[0047] Step 1: Add high-quality pig iron, scrap steel containing carbon steel components, nickel ingots and aluminum ingots into the intermediate frequency induction furnace. During the smelting process, the temperature of the molten iron is kept at 1465°C to obtain molten iron with qualified chemical composition;

[0048] Step 2: Add an inoculant of 0.35% of the total amount of molten iron into the spheroidizing ladle with slag collecting bags with filters installed at the upper end and the bottom, and use an intrusive spray gun to spray blunt into the sphero...

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Abstract

The invention relates to a method for preparing a novel nodular cast iron railway turnout accessory. The nodular cast iron railway turnout accessory is prepared from, by mass percent, 4.3%-4.7% of carbon, 2.3%-2.5% of silicon, 0.5%-0.7% of nickel, 0.01%-0.06% of aluminum, 0.02%-0.03% of magnesium, not larger than 0.2% of manganese, not larger than 0.02% of phosphorus, not larger than 0.01% of sulphur and the balance iron. The method for preparing the novel nodular cast iron railway turnout accessory comprises the following steps that 1, high duty pig iron, carbon steel containing steel scraps,nickel ingots and aluminum ingots are added into a medium-frequency induction furnace, it is guaranteed that the temperature of molten iron ranges from 1450 DEG C to 1500 DEG C in the smelting process, and molten iron is prepared; 2, a nucleating agent accounting for 0.3%-0.5% of the total amount of the molten iron is added into a balling bag, an invasive spray gun is adopted, natural gas is adopted as a carrier, passivated granular magnesium is sprayed into the balling bag, the molten iron is continuously and stably introduced into the balling bag, and the pressure intensity in the balling bag is set as 7*105 MPa to 8*105 MPa; 3, pouring is carried out; and 4, a casting is subjected to heat treatment, and the nodular cast iron railway turnout accessory is obtained. According to the method, the balling rate of the novel nodular cast iron railway turnout accessory is high, and high low temperature impact resistance and impact plasticity are achieved.

Description

technical field [0001] The invention relates to the technical field of production of railway turnout fittings, in particular to a preparation method of a novel nodular cast iron railway turnout fitting. Background technique [0002] The train turnout is an important component of the railway track structure, and it is the special equipment required for the wheels of the rolling stock to transfer from one rail to another. The turnout rail will be subjected to huge wheel impact load when the locomotive passes. At this time, in addition to the greatly increased static load, it will also bear the largest dynamic load on the rail, and the working conditions are extremely harsh. Therefore, in order to ensure the long-term, stable and safe operation of the rails of the train turnout, the steel for the train turnout must have excellent comprehensive properties. [0003] Existing railway turnout fittings are made of nodular cast iron to make them have excellent properties such as hig...

Claims

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Application Information

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IPC IPC(8): C22C33/12C22C37/04C22C37/10C21C1/10B22C9/22C21D5/00C21D9/00
CPCB22C9/22C21C1/105C21D5/00C21D9/0068C22C33/12C22C37/04C22C37/10Y02P10/143Y02P10/20
Inventor 王丽娟
Owner JIANGSU JINYULONG RAILWAY EQUIP
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