Railway vehicle axle repair process

A technology for railway vehicles and axles, applied in metal material coating process, coating and other directions, can solve problems such as environmental hazards of abandoned axles, high axle replacement costs, wheel seat cracks and unloading grooves, etc., to achieve environmental friendliness and eliminate residual stress. , the effect of reducing the harm to the environment

Inactive Publication Date: 2015-04-01

SOUTHWEST JIAOTONG UNIV

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AI-Extracted Technical Summary

Problems solved by technology

However, it can be seen from the inspection of the axles in the factory that a considerable part of the axles have been damaged within less than 10 years of use, and the defects are mainly wheel seat cracks and unloading groove cracks.

[0004] At present, there is little re...

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Abstract

The invention discloses a railway vehicle axle repair process. The process comprises the steps of pretreatment, laser cladding, residual stress relaxation and machining, wherein in the laser cladding step, the adopted metal powder comprises, by mass, 0.1-0.25% of carbon, 17.5-28% of chromium, 10.5-16% of nickel, 0-0.65% of boron, 0.12-1.0% silicon, 0-4.5% of molybdenum, 0-0.8% of manganese and the balance being iron. A vehicle axle repaired through the process is small in microstructure, free of the defects such as air holes, slag inclusion and cracks and capable of meeting the requirement for use performance; the service life of the repaired vehicle axle reaches or exceeds that of a new axle. The railway vehicle axle repair process has the advantages that operation is easy, the controllability is good, the damaged vehicle axle can be repaired quickly in a short time, the cost for replacement of the damaged axle with the new axle is lowered, the use cost of the vehicle axle is lowered, harm of the discarded vehicle axle to the environment is reduced, and environmental friendliness is achieved.

Application Domain

Metallic material coating processes

Technology Topic

SlagAutomotive engineering +9

Examples

Experimental program(6)

Example Embodiment

[0021] Example 1: A repairing process for railway vehicle axles, which includes the following steps:

[0022] (1) Pre-treatment: Machining the damaged part of the axle to remove the defects of the damaged part, and then use acetone and absolute alcohol to remove the oil and rust within 20mm of the damaged part and the surrounding area;

[0023] (2) Laser cladding: After step (1), the surface of the damaged part of the axle is scanned by a semiconductor laser with lateral powder feeding along the damaged part, and the surface of the damaged part of the axle is melted to form a molten pool, and the metal powder is flowed 15L/min of argon gas is blown into the molten pool to melt and repair the damaged parts of the axle. The metal powder is composed of the following mass percentages:

[0024] 0.1% carbon, 17.5% chromium,

[0025] 10.5% nickel, 0.12% silicon,

[0026] The rest is iron,

[0027] The parameters of the laser cladding process are as follows:

[0028] Laser power 2000W, scanning speed 6mm/s,

[0029] Powder feeding voltage 14V, spot diameter 5mm,

[0030] Overlap rate 0.5;

[0031] (3) Elimination of residual stress: the repaired axle damage part is heat treated to eliminate residual stress. The heat treatment process adopts local heat treatment, the heat treatment temperature is 300℃, the holding time is 2h, and then slowly cooling;

[0032] (4) Machining: Perform colored flaw detection and magnetic particle flaw detection on the surface of the damaged part of the axle to eliminate stress, check whether there is no crack defect, check the dimensional accuracy and position accuracy of the axle, and meet the requirements, and finally eliminate the residual stress of the axle The damaged part is machined to meet the final dimensional accuracy and finish requirements of the axle.

Example Embodiment

[0033] Example 2: A repairing process for railway vehicle axles, which includes the following steps:

[0034] (1) Pre-treatment: Machining and hand-grinding the damaged part of the axle at the same time to remove the defects of the damaged part, and then use acetone and absolute alcohol to remove the oil and rust within 20mm of the damaged part and the surrounding area;

[0035] (2) Laser cladding: After step (1), the surface of the damaged part of the axle is scanned with a coaxial powder-feeding fiber laser along the damaged part, and the surface of the damaged part of the axle is melted to form a molten pool, and the metal powder is flowed 15L/min of argon gas is blown into the molten pool to melt and repair the damaged parts of the axle. The metal powder is composed of the following mass percentages:

[0036] Carbon 0.25%, chromium 17.5%,

[0037] Nickel 16%, boron 0.65%,

[0038] 1% silicon, the rest is iron,

[0039] The parameters of the laser cladding process are as follows:

[0040] Laser power 2500W, scanning speed 6mm/s,

[0041] Powder feeding voltage 10V, spot diameter 3mm,

[0042] Overlap rate 0.4;

[0043] (3) Elimination of residual stress: the damaged part of the axle after repair is shot peened to eliminate the residual stress. The shot peening process uses stainless steel shots, the size of the shot is 0.4mm, and the shot blasting speed is 80m/s;

[0044] (4) Machining: Perform colored flaw detection and magnetic particle flaw detection on the surface of the damaged part of the axle to eliminate stress, check whether there is no crack defect, check the dimensional accuracy and position accuracy of the axle, and meet the requirements, and finally eliminate the residual stress of the axle The damaged part is machined to meet the final dimensional accuracy and finish requirements of the axle.

Example Embodiment

[0045] Example 3: A repairing process for railway vehicle axles, which includes the following steps:

[0046] (1) Pretreatment: Manually polish the damaged part of the axle to remove the defects of the damaged part, and then use acetone and absolute alcohol to remove the oil and rust within 20mm of the damaged part and the surrounding area;

[0047] (2) Laser cladding: After step (1), the surface of the damaged part of the axle is scanned by a semiconductor laser with lateral powder feeding along the damaged part, and the surface of the damaged part of the axle is melted to form a molten pool, and the metal powder is flowed 11L/min argon gas is blown into the molten pool to melt and repair the damaged parts of the axle. The metal powder is composed of the following mass percentages:

[0048] 0.1% carbon, 28% chromium,

[0049] Nickel 10.5%, boron 0.65%,

[0050] Silicon 0.12%, Molybdenum 4.5%,

[0051] The rest is iron,

[0052] The parameters of the laser cladding process are as follows:

[0053] Laser power 2100W, scanning speed 6mm/s,

[0054] Powder feeding voltage 11V, spot diameter 4mm,

[0055] Overlap rate 0.5;

[0056] (3) Elimination of residual stress: the repaired axle damage parts are heat treated to eliminate residual stress. The heat treatment process adopts local heat treatment, the heat treatment temperature is 300℃, the holding time is 1h, and then slowly cooling;

[0057] (4) Machining: Perform colored flaw detection and magnetic particle flaw detection on the surface of the damaged part of the axle to eliminate stress, check whether there is no crack defect, check the dimensional accuracy and position accuracy of the axle, and meet the requirements, and finally eliminate the residual stress of the axle The damaged part is machined to meet the final dimensional accuracy and finish requirements of the axle.

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Description & Claims & Application Information

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the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

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Classification and recommendation of technical efficacy words

Relief of residual stress
Good metallurgical bond

Railway vehicle axle repair process

AI-Extracted Technical Summary

Problems solved by technology

Abstract

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

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