Welding method of bainitic steel frog and carbon steel rail

A technology of bainite steel and welding method, which is applied in the direction of steel rails, welding equipment, rails, etc., can solve the problems that the actual application evaluation of the welding effect is not given, and the systematic research of material welding processability, etc.

Inactive Publication Date: 2009-01-07
YANSHAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The technical content of these patents is mainly focused on the structural modification of the frog, without systemat

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] First, preheat the carbon steel rail to 400°C, and use the flash welding method to butt weld the carbon steel rail and the connecting material together. The specific process parameters during flash welding are: flash speed 3mm / s, upsetting speed 80mm / s, upsetting pressure 40MPa, and the protruding length of the material during welding is equal. The chemical composition (Wt%) of the connecting material is C0.12, Cr15.8, Ni8.4, Si0.25, S0.008, P0.008, and the rest is iron. The material is heated to 1050 ° C for 3 hours for solid solution treatment Finally, 85% austenite and 15% ferrite duplex structure is obtained. Then cut off the connecting material to 25mm, preheat the bainitic steel frog to 300°C, cut off the connecting material and flash weld the bainitic steel frog, and the process parameters of flash welding are the same as above. The welded joint was kept at 950°C for 15 minutes by medium frequency induction heating and then air-cooled. The tensile strength of t...

Embodiment 2

[0017] First, preheat the carbon steel rail to 450°C, and use the flash welding method to butt weld the carbon steel rail and the connecting material together. The specific process parameters during flash welding are: flash speed 3mm / s, upsetting speed 90mm / s, upsetting pressure 50MPa, and the protruding length of the material during welding is equal. The chemical composition (Wt%) of the connecting material is: C 0.15, Cr 15.3, Ni 7.8, Si 0.28, S 0.009, P 0.008, and the rest is iron. The material is heated to 1050°C for 3 hours to obtain 83% austenite Body and 17% ferrite duplex structure. Then cut off 25mm of connecting material, preheat the bainitic steel frog to 400°C, cut off the connecting material and flash weld the bainitic steel frog, and the process parameters of flash welding are the same as above. The welded joints were held at 950°C for 15 minutes and then air cooled. The tensile strength of the welded joint between the bainitic steel frog and the carbon steel r...

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Abstract

A method for welding a bainite steel frog and a carbon steel rail is characterized in that CrNi series austenite-ferrite dual phase steel is adopted as a connecting material; the technological process is as follows: (1) the carbon steel rail is preheated to 300-500 DEG C; (2) the carbon steel rail and the connecting material are butt-welded together; (3) the connecting material is cut and retained at the length of 20-30mm; (4) the bainite steel frog is preheated to 300-500 DEG C; (5) the retained connecting material and the bainite steel frog are flash welded; and (6) the temperature of a welding joint is preserved between 900-1,000 DEG C for 10-20 minutes, and then the welding joint is air cooled. The connecting material has the following composition (weight %): C is equal to or less than 0.2; Cr is 15-17; Ni is 7-9; Si is equal to or less than 0.3; S+P is equal to or less than 0.04; and iron is in balancing amount. The connecting material is heated to 1,050 DEG C, and then solution treatment is performed to obtain austenite-ferrite dual phase tissue, wherein the content of ferrite is 10-20%; the flash speed of flash welding is 2-3mm/s; the upset forging speed is 80-100mm/s; the upset forging pressure intensity is 40-50MPa; and the extension elongations of the material are equal during the welding process.

Description

technical field [0001] The invention relates to a welding method for a bainitic steel frog and a carbon steel rail. Background technique [0002] Frog is an important component of railway transportation, and it is the most seriously damaged part in the railway structure. At present, there are two kinds of fixed frogs used on my country's railways: one is a high-carbon steel composite frog, which is fastened by bolts. This kind of frog is not wear-resistant, and the bolts are easy to loosen. Defects such as cracks are formed at places, resulting in a significant shortening of life. The other is high manganese steel whole casting frog. High manganese steel frog has the characteristics of good toughness, load hardening and wear resistance. However, casting high manganese steel frog has unavoidable casting defects, such as porosity and shrinkage cavity. And the crystal grains are too coarse, etc., it is easy to cause longitudinal and horizontal cracks, vertical cracks, collapse...

Claims

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Application Information

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IPC IPC(8): B23K11/04B23K11/16B23K11/34B23K101/26
Inventor 张福成何畅吕博张明王天生
Owner YANSHAN UNIV
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