FP PISTON RINGS:
We have more than 2,000 models of piston ring IN STOCK, meanwhile we can produce piston ring for more than 6,000 models.
Alloy cast iron, Ductile cast iron, Steel, Alloy steel
Generally speaking, the surface treatment are divided into Chrome plated, Phosphorization, Oxidation, Sprayed Molybdenum, Nitriding, Honing piston ring etc
Good wear resistance. The chrome is hard, therefore the cast iron is not easy being inlayed into the chrome surface. Especially for the first ring, if it is chrome-plated, it can reduce at least 50% wear of the inside of liner. And also the working time is increased 3 to 5 times than those none chrome plated. The other advantage is the rest ring also can reduce the wear at least 30% compare with those without chrome coated. Nowadays, second and oil rings are also chrome coated in the high-speed engines so that the engine working time is prolonged.
For the thickness of the chrome on the surface is 0.10～
Phosphorization and Oxidation:
The phosphate coating is treated by the chemical methods and the main chemical elements for the phosphate coating is the iron phosphate or the manganese phosphate. The two chemical elements are soft, but flexible, so that the liner protruding parts touched the piston ring and shorten the initial running time. Due to the simplicity and low cost, the phosphate film is frequently used for the small engines.
Oxidation is happened in the NaOH, so that make birth to the iron oxide film. Because the phosphate film and the oxidation film is easy to be worn, it shortened the initial running time.
Because the engine oil film is easy to be broken in the high temperature, the molybdenum is sprayed on the surface of the ring. In addition, the molybdenum is with high melting point, even if there are no engine oil film on the inside of the liner, the piston ring also can work normally to prevent from scratching the cylinder liner. And also because the small holes on the molybdenum ring, they can save the engine oil. But due to the difficulty in producing, strength maintenance and the high cost, people often take the chrome instead of the molybdenum.
Nowadays the nitriding is adopted for the steel piston ring with the high hardness, high wear resistance, and less pollution. And the hardness is much higher than the chrome. It is more and more popular because of less pollution.
Honing piston ring:
The barrel face piston ring is put into the honing machine and up and down working with rotation, and then there will be the shinning line on the middle surface of the ring. The advantage of honing is to improve the scratching the engine oil, to seal the cylinder liner because of the line-contact, and shorten the initial running time.