Introduction
Nitriding is a surface hardening treatment of steel, which is widely used to improve surface hardness, wear and corrosion resistance, after which both the inner and surface of the steel are steel hard and crack resistance. It is not only used to enhance the strength of the steel surface, but also to improve its fatigue strength to the greatest extent. In addition, parts treated with nitriding can also improve their surface lubrication property, so as to reduce the friction of moving parts, and reduce the abrasion of moving parts. Nitriding is also known as gas nitriding or soft nitriding. The process involves diffusing nitrogen into the surface layer of the steel. Nitrogen combines with Fe atoms to form a compound known as (Fe-N) compound. The diffusion of nitrogen particles into the steel increases its surface toughness, wear resistance and corrosion resistance. This article will discuss the common defects of nitriding (soft nitriding) treatment.
Common Defects
1. Dimpling: Dimpling is the formation of pits in the surface of parts treated with nitriding treatment. The pits usually have a diameter of less than 0.5mm. This defect is usually caused by metal particles sticking to the treated surface.
2. Cracking: Cracks can form on the surface of the treated steel due to overheating or rapid cooling after nitriding. Cracking is a dangerous defect which can lead to the complete failure of the part.
3. Nitridation: Nitridation is the occasional presence of excessive nitride or nitrogen compounds on the surface of treated parts. This defect results in the parts having a higher surface hardness than desired.
4. Porosity: Porosity is the presence of small holes on the surface of the parts. It is usually caused by the accumulation of gas in the steel.
5. Oxidation: Oxidation is the formation of an oxide layer on the surface of the steel. This defect is usually caused by insufficient protection of the parts during the nitriding treatment.
Conclusion
In conclusion, nitriding (soft nitriding) is a surface hardening treatment of steel, which is widely used to improve surface hardness, wear and corrosion resistance. Although it has many advantages, there are occasionally defects in the process of nitriding treatment. The common defects include dimpling, cracking, nitridation, porosity and oxidation. It is important for us to understand these defects in order to control the quality of our parts.
