Heat treatment process for surface hardening and carbonitriding of hydraulic parts

Abstract

The invention provides a heat treatment process for surface hardening and carbonitriding of hydraulic parts, which includes the following steps: a washing the hydraulic parts preparing for heat treatment to remove greasy dirt; b warming a carburizing multi-purpose furnace, and performing pre-carburizing treatment; c putting the hydraulic parts washed cleanly through the step a in the carburizing multi-purpose furnace, and performing strong carburizing; d adjusting carbon potential after the strong carburizing to perform diffusion; e putting the hydraulic parts after carbonitriding in the stepd in a quenching chamber of the carburizing multi-purpose furnace to be quenched, filtering oil and discharging from the furnace; and f washing the hydraulic parts of the step e, and putting the hydraulic parts in a tempering furnace to be tempered to obtain products.

Description

technical field [0001] The invention relates to the technical field of heat treatment, in particular to a carbonitriding heat treatment process for surface hardening of material hydraulic parts. Background technique [0002] Carbonitriding is a chemical heat treatment process in which active C and N atoms infiltrate the surface of steel parts at the same time. It is a combination of C carburizing and N carburizing chemical heat treatment processes. It has both advantages, and the C-N carburizing layer has low brittleness and toughness High and strong combination with the matrix and anti-stripping properties, there is a tendency to gradually replace C infiltration. However, in actual production, there will be various defects due to various reasons, especially the control of the hardness layer, which is an important prerequisite to ensure the quality of the C and N co-infiltration layer and the service life of the product. [0003] The carbonitriding process must strictly con...

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Problems solved by technology

[0003] The carbonitriding process must strictly control the carbonitride concentration of the carburized layer. If the content is too low, high strength, hardness and ideal residual stress cannot be obtained, which affects wear resistance and fatigue strength. On the contrary, not only a large number of uneven spots appear on the surface Blocky carbonitrides, increased brittleness, and will increase the amount of retained austenite after quenching, affecting the hardness layer and fatigue strength, and the quality control of the hardness layer is a technology that is difficult to master in today's industry. We invented a heat treatment process that can control the hardness layer