Low-temperature gas-phase multi-element strengthening method preset with three-stage process

Abstract

The invention discloses a low-temperature gas-phase multi-element strengthening method preset with a three-stage process. The low-temperature gas-phase multi-element strengthening method preset with the three-stage process comprises the following steps: (1) performing sand blasting or pickling on a to-be-treated workpiece, and putting the to-be-treated workpiece subjected to sand blasting or pickling into a clamp; (2) putting the clamp into a heating furnace for heat treatment: (21) increasing a temperature in the heating furnace to 350 DEG C, preserving the heat for 20-30 minutes, warming, and introducing ammonia gas into the heating furnace; (22) when the temperature is increased to 500-560 DEG C, introducing ammonia gas and a permeating agent A into the heating furnace, preserving the heat for 1-3 hours and continuously warming; (23) when the temperature is increased to 570-670 DEG C, introducing the ammonia gas and the permeating agent A into the heating furnace again, preserving the heat for 0.5-1.5 hours, and cooling; and (24) when the temperature is reduced to 500-520 DEG C, introducing ammonia gas and a permeating agent B into the heating furnace, preserving the heat for 1-3 hours, and then, cooling and discharging. The low-temperature gas-phase multi-element strengthening method preset with the three-stage process solves the problem that temperature range is relatively narrow, and can carry out alpha-Fe high-temperature-section surface modifying and strengthening treatment at a temperature being 500-670 DEG C.

Description

technical field [0001] The invention belongs to the field of heat treatment, and in particular relates to a low-temperature preset three-stage gas phase multiple strengthening method. Background technique [0002] At present, low-temperature chemical heat treatment adopts: nitriding, nitrocarburizing, liquid nitrocarburizing (such as QPQ), etc. These methods all have shortcomings such as single infiltration element, long time, shallow infiltration layer, high cost and poor quality stability, narrow application temperature range (generally 500-590°C) and serious environmental pollution (such as QPQ). At present, the national "Industrial Structure Adjustment Catalogue" has specified that salt solution soft nitriding (QPQ belongs to the restricted category) is a restricted process range. Contents of the invention [0003] In order to improve the above-mentioned problems, the object of the present invention is to provide a low-temperature preset three-stage gas-phase multi-co...

AI Technical Summary

Problems solved by technology

These methods all have shortcomings such as single infiltration element, long time, shallow infiltration layer, high cost and poor quality stability, narrow application temperature range (generally 500-590°C) and serious environmental pollution (such as QPQ). At present, the national "Industrial Structure Adjustment Catalog" has clarified that salt solution soft nitriding (QPQ belongs to the restricted category) is a restricted process range