In order to make fasteners more effective use, we use fasteners in the need for regular maintenance, such as regular cleaning of fasteners, which can improve the use efficiency of fasteners.
First, improper rinsing
For large size fasteners, the polymer solution is often used to quench and rinse with alkaline detergent before quenching, and the hardened fasteners are rusted inside. The analysis of infrared spectrometer shows that there are sodium, potassium and sulfur besides iron oxide, which indicates that the alkaline adhesive is adhered to the inner part of the fastener, and it may be potassium hydroxide, sodium carbonate or similar substance to promote its rust. Rinse the fasteners to check if there is excessive contamination, and recommend changing the rinse water regularly. In addition, adding rust inhibitor to water is also a good way.
Two, surface residue
A white residue high strength screw, were analyzed by infrared spectroscopy confirmed the phosphide. There is no acid cleaning agent, and the washing tank inspection found that the tank has a higher carbon solubility, should be regularly drained out of the tank, often detect the concentration of lye in the rinse tank level.
Three. Contamination during rinsing
Fasteners after quenching with Portland cleaning agent, and then rinse, XX appears on the surface of solid material, will use the infrared spectrometer to analysis it is confirmed, inorganic silicate and ferric oxide. This is due to incomplete rinsing and silicate residue on the surface of the fastener.
Four. The stacking of fasteners is unreasonable
After the fastener is tempered, there is a sign of discoloration. The ether is soaked and the ether is evaporated to find the remaining oily residue. This substance is a high content lipid. It is indicated that the fastener is contaminated by cleaning agent and quenching oil in the rinsing period, melts at the heat treatment temperature, leaving a chemical burn scar, which proves that the fastener surface is not clean. The mixture of base oil and ether in quenching oil is analyzed by infrared spectrometer. Ether may come from quenching oil additives. Oil quenching analysis confirms the mesh belt furnace in fasteners: heating due to improper dumps, fasteners in the quenching oil in mild oxidation, but almost negligible, this phenomenon is associated with the cleaning process, rather than the problem of quenching oil.