Vulcanized powder metallurgy products
Vulcanization process is relatively simple, does not require specialized equipment, the process is as follows:
Sulfur placed in a crucible and heated to melt, the temperature control in the 120 ~ 130 ℃, the sulfur flow at this time is better, if the temperature is too high, is not conducive to dipping. The need impregnated sintered article preheated to 100 ~ 150 ℃, then the article is immersed in molten sulfur was immersed for 3 to 20 minutes, not been pre-impregnated article 25 to 30 minutes. Depending on the density of the article, the wall thickness and to determine the required amount of immersion immersion time. Low density, wall thickness of immersion time may be less; and vice versa. Dip After removing products, shed the remaining sulfur. Finally, the impregnated products into the furnace, hydrogen-protection, can also be protected with charcoal, heated to 700 ~ 720 ℃ incubated 0.5 to 1 hour, at this time, sulfur and iron immersed in the role of iron sulfide. 6 to a density of 6.2 g / cm 3 article, sulfur enters about 35 to 4 percent (by weight). In order to make immersed heating firing is part of pores formed iron sulfide sulfur.
After the curing process of sintered products, can be oiled and finishing and other treatment.
Powder metallurgy porous oiled anti-friction products is an important process, increases the corrosion resistance of powder metallurgy products, improve the wear resistance and prolong its service life. Oiled processing after sintered iron base oil bearing, lubricating oil into the products in the pore, namely when the axis of rotation, with the set of kinetic friction, heat production, make the bearing temperature rise, oil in thermal expansion, from the pore flow between shaft and shaft sleeve automatic oil supply, the formation of oil film lubrication anti-friction effect. Oiled also can prevent products by oxidation.