1. Nitriding treatment will form a dense nitride layer (such as Fe₃N, Fe₄N, etc.) on the surface of the piston ring, with a hardness of 900-1200 HV, which is much higher than that of ordinary steel (about 200-300 HV), thus greatly reducing wear caused by friction and extending the service life. Under high-load operating conditions of the engine, the nitride layer can effectively resist sliding friction with the cylinder wall, reducing scratches and the risk of scoring.

2. Enhanced high-temperature performance: It can usually maintain high hardness and stability at 500-600°C, avoiding softening or failure caused by thermal expansion of the piston ring.

3. Improved corrosion resistance: The nitride layer can effectively isolate the corrosion of acidic gases (such as sulfides, nitrogen oxides) and condensates produced by combustion, reducing the corrosion rate of the piston ring, especially when using low-quality fuel or alcohol gasoline.

4. Reduce the friction coefficient: The surface after nitriding treatment has self-lubricating properties, which can reduce the frictional resistance with the cylinder wall, improve the engine mechanical efficiency (reduce friction loss by about 5-10%), and thus improve fuel economy.

1. High hardness and wear resistance: The hardness of hard chrome plating can reach 800-1000HV. Suitable for low and medium speed engines, it reduces wear caused by friction, and under good lubrication conditions, it can effectively extend the life of the piston ring.

2. Surface finish and low friction: The chrome plating surface is smooth, which can reduce the friction coefficient with the cylinder wall (about 0.4-0.6).

3. Corrosion resistance: The chromium layer at room temperature has a certain protective effect on combustion products (such as water and weakly acidic substances).

4. High temperature performance: The hard chromium layer maintains its performance below 400°C.

1. Extreme wear resistance: The hardness of the PVD coating can reach 2000-3000HV, far exceeding the nitride layer (900-1200 HV) and the chrome plating layer (800-1000 HV).

2. Ultra-low friction coefficient: The friction coefficient can be as low as 0.1-0.2, significantly reducing the frictional resistance between the piston ring and the cylinder wall.

3. Energy saving effect: Reduce engine internal consumption, improve mechanical efficiency, and improve fuel economy (reduce friction loss by about 3-8%).

4. High temperature stability: Heat resistance The PVD coating can maintain structural stability at high temperatures of 600-800°C*, avoiding high-temperature softening.

1. Ultra-low friction and self-lubrication: The friction coefficient of the DLC coating can be as low as 0.05-0.1 (under dry friction conditions). Reduce engine internal consumption, improve mechanical efficiency (friction loss reduced by 8-15%).

2. Ultra-high hardness and wear resistance: The hardness of the DLC coating can reach 2000-4000 HV, which is 4-5 times that of the chrome plating layer, and the wear resistance is increased by 3-5 times. Abrasive wear resistance can still maintain surface integrity in dusty environments or lubricating oil contamination (such as metal debris), avoiding scratches on the cylinder wall.

3. High temperature stability: The DLC coating maintains stable performance within 500-700°C. The thermal expansion coefficient of DLC is close to that of the metal substrate, and the coating and substrate are firmly bonded at high temperatures, and are not easy to peel off.

4. Chemical inertness and corrosion resistance: DLC has strong resistance to acidic combustion products (sulfides, nitrogen oxides), corrosive components in alcohol gasoline and biodiesel. Inhibit the deposition of carbon deposits and sludge on the surface of the piston ring, maintaining long-term cleanliness.