What is the method of wash oil residue on the surface of the fasteners

Not good cleaning method, mainly for cold heading processing or machining surface of fasteners of cooling oil residual oil, oil heat treatment quenching fastener surface residual oil after cleaning.

01 alkaline cleaning method

The simple alkaline cleaning is heated directly or indirectly heating cleaning tank, cleaning fluid N2CO3 or NaOH aqueous solution is 3% ~ 10%. For carburizing and carbonitriding self tapping screw, tempering before the middle of the multi-purpose cleaning heating to 50 ~ 70 ℃ 5% ~ 10% sodium carbonate solution. Connection type mesh belt furnace which belongs to and so on. Fasteners, commonly used cleaning spray and immersed in a double way, if use hot water washing effect is better, after the use of high pressure air for drying. Alkaline cleaning methods * main drawback is that the effect is not very good, especially in blind holes and grooves of fasteners to blotch and residue. For alkaline cleaning produce waste water must be carried out and treatment, and recovery of waste oil, meet the requirements of environmental protection of the relevant before discharge.

02 metal cleaning agent cleaning method

Alkaline cleaning method to overcome the shortcomings, and improve the cleaning effect, the current can be used for metal cleaning agent, cleaning agent in 40 ~ 70 ℃ water dilute solution of 1% ~ 3%, the fasteners in solution immerse 15 ~ 20 min, and then rinse with hot water, using dryer after dehydration processing. Can be used while adding the washing machine. Metal cleaning agent cleaning method of defect is expensive, and has a bad smell, has certain corrosion effect to the fastener, wastewater pollution of the environment, therefore, must to deal with waste water, and recycling waste oil.

03 organic solvent cleaning method

Using trichloroethane, trichloroethylene, etc organic solvent cleaning, cleaning effect is good. Under normal pressure by immersion or spray cleaning quenching fasteners, environmental pollution by organic solvent volatilization and splash. For this purpose, the application of vacuum sealed decompression solvent cleaning method of whole set, using vacuum pump to discharge air, fasteners, in the absence of air and high density vapor contact, further improve the cleaning effect, and by vacuum distillation recycling solvent and oil. After recycling the solvent content in the oil from 20% to below 4%, lower than 50 PPM trichloroethylene environmental hygiene regulations.

04 combustion degreasing method

Cold heading or machining fasteners before the heat treatment process, need to wash off the surface of the oil. To this end, can match the fasteners in degreasing furnace heating to 350 ~ 400 ℃ oil vaporization or burning, in order to reach the purpose of fasteners to oil or surface the effect of phosphorus removal. Combustion degreasing method is only applicable to cleaning before heat treatment, can also clean the cooling oil, anti-rust fluid such as light weight, low viscosity and low boiling point of oil. High viscosity, high boiling point after heavy quenching oil burning there will be a large number of residues and carbon black adhere to the surface of fasteners, can not meet the cleaning purpose.

For high cleaning the surface of the fasteners, such as aviation, automobile engine connecting rod bolt use vacuum or ultrasonic cleaning technology at present, instead of the commonly used on the atmospheric ozone layer has the damaging effects of chlorinated hydrocarbons as solvent cleaning method, can realize efficient environmental protection cleaning.