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2h Hex Nut Cleaning Strategy

Feb 24,2021 / Industry News, News / Author: ShengKui

To use 2h Hex Nut better, it needs regular maintenance, such as regular cleaning, to improve its efficiency. However, when we clean, we often find some problems, let's discuss them below.


1. Surface residue
There is a white residue on the screw, and the infrared spectrometer is used to analyze and check that the residue is phosphide. No acidic detergent was used for cleaning, and the rinse tank was checked to find that the tank liquid had carbon solubility. The bath should be poured out regularly, and the concentration level of the lye in the rinse tank should be checked frequently.


2. Unreasonable stacking
After 2h Hex Nut tempered, there are signs of discoloration. Soak them in ether. After the ether had evaporated, an oily residue was found. These substances are high in lipids. The results showed that it was contaminated by detergent and quenching oil during rinsing, and melted at the heat treatment temperature, leaving traces of chemical combustion. The surface of these materials is not clean. Infrared spectrometer analysis is a mixture of base oil and ether in quenching oil. The ether may come from the addition of quenching oil. The analysis and inspection of the quenching oil in the mesh belt furnace confirmed that it would stack up unreasonably during heating, and there were traces of slight oxidation in the quenching oil, which were almost negligible. This phenomenon is related to the cleaning process, not the quenching oil. problem.


3. Alkali combustion
The high-strength screw has a uniform and flat oil-black outer surface after the heat of quenching. However, there is a visible area of ​​the courseware in the outer circle. Also, there are some visible areas of light blue or light red. The original bar and wire rod are coated with phosphating film to facilitate cold heading and tapping. They are directly heat treated without rinsing, cooled in quenching oil, cleaned with the alkaline cleaning agent, blow-dried (not rinsed), and returned at 550°C. When heating, take out the immersed anti-rust oil from the tempering furnace and find red spots on the threads.


It was detected that the red area on the screw was caused by alkali burning. Alkaline cleaners containing chloride substances and calcium compounds burn the steel 2h Hex Nut during the heat treatment process, leaving marks on the surface.


Steel 2h Hex Nut can not remove the surface alkaline substances in the quenching oil, which burns the surface in the high-temperature austenite state, and aggravates the damage in the next step of tempering. It is recommended to clean and rinse thoroughly before heat treatment to thoroughly remove the alkaline residue that can cause 2h Hex Nut burns.