In automotive sector, engine cylinder liners have their own significance. Cylinder liners are important part of engine block. The cylinder liner is exposed to high temperatures while it is operated with in the internal combustion engine. The piston will come in contact with the inner surface of the cylinder liner during the reciprocating motion.
Properties like hardness and wear resistance of cylinder liner plays important role in evaluating the functioning of the cylinder liner. These properties can be improved by using special techniques like nitriding, carburizing, etc.
Nitriding is a thermochemical process in which the surface of the metal (ferrous) is added with nitrogen through which the wear resistance of the components improves. The diffusion process is based on the nitrogen solubility in ferrous metal, such as iron.
As nitriding is one of the critical techniques used for surface hardening of the material, there are many industries using this technique. It is used in the making of aircraft, textile machinery, bearings, and automotive components like crankshafts, valves, and piston rods.
Why Nitriding and Why Not Something Else?
Nitriding technique is preferred by engineers because it doesn’t need a phase change. This means steel remains in the same ferrite phase during the entire process. However, in the traditional process, there will be a phase change from ferrite to austentite and austentite to martensite.
Quenching process is not needed as free cooling takes place during the nitriding process. Nitriding technique enhances the fatigue life, offers anti-galling properties and high surface hardness.
Nitriding process can be done at low temperatures which is not possible in other hardening techniques. This method is cost effective.
There are Three Types of Nitriding Process:
- Gas nitriding
- Salt bath nitriding
- Plasma nitriding
In gas nitriding, the nitriding surface is formed on the component surface by using the nitrogen acquired from the ammonia diffusion. Gas nitriding process happens inside a furnace by maintaining the required conditions. It’s parameters are:
- Gas flow
- Gas activity control
- Process chamber maintenance
- What are The Advantages of Nitriding Process?
- It is low temperature process
- No phase change during the process
- Improves fatigue strength
- Enhances wear resistance
- Offers anti-galling properties
Besides all of these advantages, there are limitations of nitriding process- it cannot be applied to stainless steel and it results in the increase in component volume.
For More Details on Nitriding, Contact Engine Cylinder Liners Manufacturers.