Low-carbon steel laser surface carburizing method

Abstract

The invention discloses a low-carbon steel laser surface carburizing method which comprises the following steps: 1) preparing a colloid mixture of liquid paraffin and carbon powder with the content of 65-70%; 2) preparing a paraffin and carbon powder composite film on the surface to be coated with carbon, wherein the thickness of the composite film is 2.5-3mm; and (3) the surface of the low-carbon steel is subjected to laser scanning in the atmosphere environment with the oxygen content being 1 ppm or below so as to be subjected to carburizing treatment. Low-carbon steel is subjected to carburizing treatment through the laser surface carburizing technology, and the surface hardness and the fatigue performance of the part can be improved. A special carbon coating mode is adopted, carbon powder is preset efficiently, and meanwhile recycling of the carbon powder and paraffin is achieved. Therefore, a simple, efficient, green and environment-friendly novel treatment method can be provided for surface strengthening of low-carbon steel metal parts, and the service life of the metal parts is prolonged.

Description

technical field [0001] The invention relates to the technical field of heat treatment strengthening of low-carbon steel, in particular to a laser surface carburizing method for low-carbon steel. Background technique [0002] Due to its low carbon content, low-carbon steel cannot obtain a high-strength and high-hardness martensitic structure after quenching, and generally requires carburizing treatment. Due to its long holding time and slow cooling rate, conventional carburizing treatment is prone to produce coarse martensite structure and carbide phase, which is extremely unfavorable to the toughness and fatigue strength of parts. [0003] Laser surface carburizing technology is to use the laser beam of energy density to quickly scan the metal parts, so that the surface temperature rises at a very fast speed above the austenite transformation temperature and below the melting point, and the carbon element quickly diffuses into the surface of the metal parts. When the laser ...

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Problems solved by technology

[0004] However, if the traditional direct powder laying or physical deposition method is used to pre-set the toner, it is easy to cause the toner to be not firmly bonded to the substrate, there are many holes in the toner layer, and oxygen and moisture remain in the toner gap, which will affect the entire process. Laser surface carburizing process

Especially for nano-scale carbon powder with high activity, it is easy to agglomerate and bond, and it is difficult to spread powder

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