(1) Surface hardness test In order to make the depth of indentation less than the thickness of the layer and ensure the accuracy of the test results, the micro Vickers hardness is adopted. The selected test parameters are: 25 g load and 15 s holding time. Each sample is...
The sample is taken from the edge, 1 / 2R and center of lzqt600-3 ductile iron profile. It is first polished by coarse to fine sandpaper, and then polished. It is necessary to ensure that there is no scratch on the metallographic surface of the sample. During polishing, the...
From the development and research trend of chemical heat treatment in atmosphere in recent years, it is still a hot research topic to improve the infiltration rate, multi-element co infiltration and low temperature co infiltration and select the suitable economic and green technology in actual production. At present, the...
When the piston pump works under high hydraulic pressure, abrasive wear and adhesive wear are the main failure causes of the key friction pairs of the piston pump. The scratch and material falling on the surface of friction pair are caused by abrasive wear. This is because the lubricating...
Nowadays, friction, lubrication and wear are the three most important research topics in tribology. Friction will cause wear, resulting in the failure effect of mechanical parts, which is generally caused by one of the three factors of wear, corrosion and fatigue, and is closely related to the life and...
The diffusion coefficient of nitrogen atom in α – Fe is larger than that of carbon atom. The main mechanism of nitriding is nitriding when the temperature is less than 600 ℃. The surface defects of carbon steel or pure iron are easy to produce after the surface treatment....
Soft nitriding, also known as nitrocarburizing, is a process of infiltrating nitrogen into the surface of workpieces and also carbon elements. Nitriding occupies a dominant position, and carburizing is used as an auxiliary. The treatment temperature ranges from 500 ℃ to 600 ℃. Gas medium, molten salt or granular...
Carbon and nitrogen elements are infiltrated into the workpiece surface at the same time. The process is called carbonitriding. The treatment temperature of this process is lower than the ordinary carburizing temperature, which is about 700 ℃ ~ 960 ℃. The most widely used temperature is between 700 ℃...
In the presence of active nitrogen atoms in the gas, liquid or solid as the medium, under a certain temperature and time treatment on the surface of parts for nitrogen infiltration, this process is called nitriding or nitriding. This chemical heat treatment process was first used on the surface...
Carbon atoms are infiltrated into the surface of steel samples, and carburizing layer is formed on the surface of steel samples. This chemical heat treatment process is called carburizing treatment. The hardness and wear resistance of the sample surface are greatly improved by using this process. The famous Russian...