A device for nitrogen arc in-situ metallurgy pre-laying nitride to realize nitrogen increase on steel surface

Abstract

The invention relates to the field of surface treatment of materials, in particular to a device for realizing nitrogen increment on the surface of steel by pre-laying nitride through nitrogen arc in-situ metallurgy. Mixed nitride alloy powder is laid on the surface of steel base material to be treated. The nitride alloy powder and part of the steel base material are heated and smelted through a nitrogen arc. A molten pool is stirred through electromagnetic stirring with an electric arc and swinging of a welding gun so that alloy elements in the nitride alloy powder and the molten base material can be fully smelted and mixed. After the molten pool is cooled and solidified, a high-nitrogen steel layer is formed on the surface of the steel. The thickness of the high-nitrogen steel layer prepared through the device can reach the millimeter level or even the centimeter level as needed. The high-nitrogen steel layer can obtain a high nitrogen content which is far lager than the maximum nitrogen content obtained through a common surface nitrogen increment treatment method.

Description

technical field [0001] The invention relates to the field of material surface treatment, specifically a method for increasing nitrogen on the steel surface by using nitrogen arc in-situ metallurgy to pre-lay nitrides, which is suitable for high-strength corrosion-resistant treatment of surfaces such as low-carbon steel, low-alloy steel, and stainless steel. Background technique [0002] Common surface nitriding methods include gas nitriding and ion nitriding. [0003] Gas nitriding can adopt general nitriding method (ie isothermal nitriding) or multi-stage (two-stage, three-stage) nitriding method. The former is that the nitriding temperature and ammonia decomposition rate remain unchanged throughout the nitriding process. The temperature is generally between 480-520°C, the decomposition rate of ammonia gas is 15-30%, and the holding time is nearly 80 hours. This process is suitable for parts with shallow penetration, strict distortion requirements, and high hardness requi...

AI Technical Summary

Problems solved by technology

Coat the prepared slurry on the surface of the part and dry it, then use a nitrogen arc to weld it. The slurry does not contain nitrogen elements, and the effect of increasing nitrogen by nitrogen arc alone is not obvious, and it takes time to dry. If it is not completely dried, it may hydrogen induced cracking

Images