Method of realizing low-temperature nitriding of steel part in complex shape

Abstract

The invention discloses a method of realizing low-temperature nitriding of a steel part in a complex shape. The method specifically comprises the following steps of: cutting a pure iron plate into a square plate by linear cutting, grinding and polishing the surface of the square plate by abrasive paper, and then conducting ultrasonic cleaning and blow-drying; preparing an oxide layer with a certain thickness and of a nano structure on the surface of a sample through an anodic oxidation method; reducing the sample subjected to anodic oxidation at a certain temperature to obtain elemental iron of a nano structure, and then realizing surface nanocrystallization; and conducting gas nitriding treatment on the reduced sample at a certain temperature. As being a chemical method, the method can achieve surface nanocrystallization of the steel part in the complex shape, can use the nanocrystallization structure to lower the nitriding treatment temperature and the process period of the steel part in the complex shape, promotes the rapid diffusion effect of the nano structure to be really applied and achieves the purposes of reducing deformation and energy consumption.

Description

technical field [0001] The invention relates to the field of surface chemical treatment of iron and steel parts, in particular to a method for realizing low-temperature nitriding of iron and steel parts with complex shapes. Background technique [0002] Nitriding is a commonly used surface modification method for steel parts, which can effectively improve the surface hardness, wear resistance, fatigue resistance, corrosion resistance and seizure resistance of parts. However, due to the influence of atomic diffusion heat and kinetics, nitriding of steel often requires a higher processing temperature (above 500°C) and a longer process cycle. Such a process not only consumes a lot of energy, but also can easily cause the decline of the mechanical properties of the core and the deformation of the appearance after the parts are processed at high temperature for a long time. Especially for precision parts, the phenomenon of waste products often occurs. Therefore, reducing the nit...

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Problems solved by technology

[0004] At present, most of the methods that can realize the nanometerization of the surface of metal materials are strong plastic deformation methods, such as surface mechanical grinding (SMAT), ultrasonic shot peening (USSP), surface mechanical grinding (SMGT), supersonic particle bombardment (SFPB), etc. When these methods are used as pretreatment before nitriding of iron and steel parts, although they can speed up the diffusion rate and reduce the treatment temperature, there are still some problems, such as the inability to deal with large-sized or complex-shaped parts, and the surface roughness of the material after treatment Substantial increase and easy to produce microcracks, etc.

In response to the above problems, relevant researchers have proposed new surface nanotechnology, such as laser shock peening, water jet impact, etc., but there are also disadvantages such as expensive equipment and complicated processes.

Therefore, there is currently no method that is simple in process and capable of nanosizing the surface of complex steel parts to promote low-temperature nitriding

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