Powder metallurgy products, oil-soaked porous friction reduction is an important process, can increase the powder metallurgy products of corrosion resistance, improved abrasion resistance, extending its life.The sintered iron-based oil bearing oil dip treatment, i.e., the lubricating oil into the pores of the article, when the shaft is rotated, and the occurrence of dynamic friction sleeve, heat, temperature rise of the bearing, the oil case of thermal expansion, flows out from the pores to the shaft and sleeve play between automatic oil, lubricating oil film formation and friction reduction. Oiled also can prevent products by oxidation. Oil immersion method can be divided into ordinary oiled, heating oil and vacuum oiled.
Ordinary immersion oil:put clean the sintering products in the oil (typically 20 to 30 engine oil)immersion. Oil under capillary force article, the article is immersed into the pores. This method is low-oiled efficiency, long time immersion oil, need a few hours, with the oil content of the products is not high.
Heating oil immersion: put clean sintered products in 80 ~ 120 ℃ in hot oil soak for 1 hour. Due to the products, heating the air inside the open pore expand, make part of the air be ruled out. After cooling, the rest of the air and contraction, put the oil into the pore. Because of the hot oil liquid, high lubricity, and thus can be more oil immersed into the products. The immersion method efficiency is higher than ordinary oil leaching rate.
Vacuum immersion oil:clean up of the sintering products in vacuum box, sealed fit to 720 – mm Hg, then to vacuum box into the oil, and then heated to 80 ℃, 20 ~ 30 minutes. Due to the air pumped out the products open pore, the oil can be in 10 minutes into products. This method is high efficiency, high speed immersed.
Another form of this method, the article is first placed in the air out of the vacuum chamber, and then the pre-heated oil pass into a vacuum oven, cover up the article, and then turned on the vacuum box and the atmosphere, oil That is quickly immersed into the article pores.