SU833375A1 - Method of producing steel powder - Google Patents

Description

I

The invention relates to metallurgy powders 58, in part, to methods for producing steel powder.

A known method for producing steel powder consists in restoring the scale of low-carbon steels with gaseous or combined recovery; by the grinding agent, grinding of the obtained speca, sifting and separation of the powder 1.,

The disadvantage of this method is the high cost of the resulting powder,

The closest to the invention in technical essence and the achieved effect is the method of obtaining steel powder from waste operations of bearing production, which consists in drying the mixture when in an atmosphere of dissociated ammonia for 0.2-2 hours the introduction of 3% carbon black into the mixture and subsequent annealing in reducing gas atmosphere at 1050С

for 1.5-2 hours, grinding SPECA and sieving powder 2.

The disadvantages of this method are the high cost of the powder associated with the duration of the recovery process, the need to use carbon black and the use of a reducing gas that is dried from oxygen and requires a separate collection of grinding and grinding waste from bearing plants and the use of Only waste opilovrch-. operation: diy, which limits the drilling base for the production of steel powder.

The purpose of the invention is to reduce the cost of the powder and expand the raw material base for its production.

Claims (2)

The goal is achieved by the fact that in the method of obtaining steel powder, including annealing of the charge in an atmosphere of reducing gas, grinding of cake and sieving of powder, the grinding operations waste or their mixture with waste operations of bearing production are used as the charge, and before annealing mechanically separating excess coolant fluid from the charge. , Replacing the drying of the charge by mechanically separating from it residues of a lubricating coolant (coolant / allows to use during reducing annealing as an additional source of reducing atmosphere the oil residues absorbed on the powder particles, which in the annealing process form a mixture of the main gas, hydrogen, carbon monoxide, dioxide carbon and moisture vapor. The ratio of CO / CO and can be controlled by the amount of moisture remaining in the charge after it is mechanically separated from the coolant. the reducing gas medium together with the decomposition products of the oil absorbed by the charge eliminates the need to use soot and cleaning the reducing gas, which makes the process and the cost of the powder cheaper. i Example: Waste grinding operations of the bearing production after 6 hours of settling are set in the furnace STN- 1 in an atmosphere of undiluted technical water and dissociated ammonia. The formation in both cases is carried out for 2 hours at 900 C. After grinding the cake in a ball mill and the magcite section laziness obtained steel powders having the following chemical composition. When reduced in technical hydrogen,%: 4 Fe 97.78; C, 0.08; Cg 1.05; Mp 0.25; S 0.02; P t), 02; , 35; an insoluble precipitate of 0.45. When reduced in dissociated ammonia,%: Fe 97.63; C, 0.17; 020,41, the content of the remaining impurities is the same as in the reduction in hydrogen. Thus, the proposed method for producing steel powder allows, in comparison with a known method, to reduce the cost of the powder and expand the raw material base for its production. The invention The method of obtaining steel powder, including annealing of the charge in the atmosphere of a reducing gas, grinding the cake and sieving the powder, is required so that, in order to reduce the cost of the powder and expand the raw material base to obtain it, The batch uses grinding waste or a mixture of them with waste from filing operations of bearing production, and before annealing, mechanical separation of excess cooling fluid is carried out from the mixture. Sources of information taken into account in the examination 1. Akimenko V, V. and others. Production of iron powder in the USSR. Direct production of iron and powder metallurgy, Thematic industry collection, Metallurgists, 1974, No. 1, pp.114-118. 2. Kutser M.YA. et al. Obtaining steel powders from ball bearing wastes. - Poroshkova metallurgists, 1963, No. 6, pp.88-93.