Six common fastener cleaning problems

In order to be able to make better use of fasteners, we use the fastener, the need for regular maintenance, such as regular cleaning of the fastener, this can improve the efficiency of the fastener. But when we wash fasteners, often found some problems, there are six major common problem.

      1, the pollution generated when rinsing

      fastenerAfter quenching silicate cleaning agent, then rinsed, the surface of the solid material XX, this was analyzed by infrared spectroscopy confirmed that the inorganic silicates and iron oxides. This is because not rinsed thoroughly due to the fastener surface residual silicate.

      2, the fastener pile unreasonable

      There are signs of discoloration after tempering fastener, soaked with ether, diethyl ether so that the volatiles found to leave an oily residue, high levels of these substances is a lipid composition. Description fasteners rinsing of contaminated cleaning agents and quenching oils in the heat Melt processing temperatures, leaving a chemical burn scars, these substances proved fastener surface is not clean. Analyzed by infrared spectroscopy, quenching oil is a mixture of the base oil and ether. Ether may come from the quenching oil additives. network Quenching oil analysis results with the furnace confirmed: when the fastener is heated by piling unreasonable, fasteners quenching oil has slightly oxidized, but almost negligible, this phenomenon is associated with the cleaning process, instead of quenching oil problem.

      3, surface residues

      White residue analyzed by infrared spectroscopy, proved to be a high-strength screw phosphide. No acidic cleaning agent, rinsing tank inspection and found that higher carbon solubility bath, the bath should be drained periodically, often to detect levels of lye rinsing tank.

      4, alkali burns

      The high strength screw having a hardening heat black uniform, smooth outer surface of black oil. But in the outer ring of orange XX visible region. In addition, there can be seen slightly bluish or reddish area. Raw bar and wire rod coated with phosphate film Conducive to tapping and cold heading, without rinsing direct heat treatment, quenching oil cooling, an alkaline cleaning agent, dry (do not rinse), 550 ℃ tempered, hot-dip rust removing oil from the furnace, the result the screw thread of the hair Now red spots.

      After the detector area is red screw alkali burns caused by alkaline cleaners containing chloride substance, calcium-containing compound during the heat treatment will burn the steel fasteners, fastener surface scarring.

      Steel fastenersIn the quenching oil alkaline substances can not be removed from the surface, resulting in a high temperature austenitic state surface burns, and in the next step tempering aggravated damage. Recommendations are thoroughly cleaned and rinsed before the heat treatment of fasteners, fastener cause burns completely removed basic residues.

      5, improper rinsing

      For large-sized fasteners are often used in aqueous polymer solution hardening, before quenching with an alkaline cleaning agent and rinsed, after quenching rusted fasteners on the inside. Analyzed by infrared spectroscopy, it was confirmed in addition to iron, but also Sodium, potassium and sulfur, have described the inside of the fastener adhered alkaline cleaners, it may be potassium hydroxide, sodium carbonate or the like, to promote rusting. Fasteners rinsing check whether there is excessive pollution, but also recommend regular exchange drift Wash water. In addition, anti-rust agent added to the water is a good way.

      6, excessive corrosion

      High-strength fastenersOften we see some black streaks in the experiments have also seen, have used inorganic and organic detergent rinse fastener before the heat treatment after quenching is still found in front of a black stripe even heat treatment carefully clean Wash will leave streaks after heat treatment. Surface residual contaminants analyzed by infrared spectroscopy, it was found higher concentrations of sulfur and calcium. With a small amount of acetic acid isopropyl alcohol, put a small piece of filter paper strength during the test at the spots off the swab, The dark spots left on the filter paper. Infrared spectrometer analysis filter paper, confirmed that calcium, sulfur, iron, manganese and chromium is one of the main elements.

      Rust in calcium and sulfur that the material is dried the quenching oil, but also in the evolution of process gas quenching substance. Because of excessive aging quenching oil, we recommend pouring old oil, add new oil, quenching oil and supervise the implementation of the process of maintenance over the entire process cycle.