Our plant deservedly ranked the first in Soviet powder metallurgy. This is the first powder metallurgic mill with a complete manufacturing cycle and one of the largest enterprise of its kind in the CIS and Europe. The plant once used to dispatch its commo
THE PLANT ALTERS ITS WAYS
Our plant deservedly ranked the first in Soviet powder metallurgy. This is the first powder metallurgic mill with a complete manufacturing cycle and one of the largest enterprise of its kind in the CIS and Europe. The plant once used to dispatch its commodities to all the regions of the former USSR.
Back in 1958 the central Soviet authorities made a decision to construct a powder metallurgic plant in Brovary town, Kiev region. The Institute of Material Science under the Ukraine’s National Academy of Sciences defined the technical performance specifications, while Dnepropetrovsk-based UkrGIPROMez institute did the project design works. Construction works commenced in 1960 and four years later the iron powder workshop was put into operation. This was the dawn of the plant’s manufacturing activities. The mill has been manufacturing iron powder commodities ever since 1967 and friction discs lined with metal powders since 1975.
Powder metallurgy applies a technology of making various metal powders that are compacted into parts with required dimensions and are subject to heat treatment (sintering). The sintering stage is performed at temperatures below the melting point of the main charge component. At the same time, the ratio of metal use comes up to 98%, thus leading to negligible losses.
The plant is the sole manufacturer of iron powder in Ukraine, the main producer of sintered iron-based P/M commodities, friction discs, commodities made of composite materials and refractory alloys.
Owing to one-of-a-kind manufacturing technologies and specific application of a whole range of products manufactured, the plant was conferred the status of a State company in 1993. In compliance with resolution No.987 of the Ukraine’s Cabinet (approved and signed on June 30, 1998), the plant acquired the name of the State Powder Metallurgic Plant.
Where is the leader of Ukrainian powder metallurgy headed now? How is the plant coping with the economic difficulties encountered in Ukraine? As a matter of fact, there are tons of problems, such as incomplete transition to market economy in business relations, continuous aggravation of the overall depression and breakdown of business contacts among former Soviet enterprises. Due to all this, the company hopes not that consumption of its products will remain on the same level and, consequently, the plant’s management fully acknowledges that it is impossible to utilize all the available productive capacities.
To ensure efficient use of equipment and productive areas, it seemed advisable to commence output of new products, which could be manufactured at the existing facilities and did not require substantial initial investments.
To meet this task, the plant has recently launched production of components and spare parts for KamAZ, KrAZ, ZIL, MAZ and GAZ trucks, as well as component parts for shock absorbers of motorcars and motorcycles.
Previously, the plant used to supply lining made of cemented silicon carbide for GC-710 and GC-500 hydro-cyclones. Since 1998 the plant has been offering ready-to-use hydro-cyclones, which can be directly installed to the customer’s production lines without any preliminary adjustments.
To meet demands of porcelain manufacturers, the plant has started producing silicon-carbide plates for kilning. These plates are durable enough to be used throughout more than 300 production cycles.
After introducing a new advanced technology, the plant has commenced manufacturing TGK-150, TGK-300 and TGK-500 crucibles for nonferrous metallurgy.
Along with various carbon fiber-reinforced and fiberglass-reinforced composites, vacuum pump’s blades and different packings, the plants has the necessary facilities to manufacture fiberglass plastic tubes of any length. These tubes are corrosion resistant and show great performance in deleterious mediums.
The plant has managed to survive and retain creative work teams owing to introduction of advanced technologies and abandonment of central-source supplies of heat power and shielding gases to productive facilities.
By using stand-alone generators of steam and shielding gases, in 1998 the plant has showed more economical performance saving 35% of natural gas against the 1997 consumption figures and simultaneously boosting output by some 23%.
At the same time, the company is doing extensive research on CIS and non-CIS markets. We fully acknowledge that the company will recover only if the product quality is constantly improved, costs are lowered and demands of our clients are satisfied completely. Naturally, our forecasts and estimates should rest on the true opportunities.
At this point of time we have defined the following main manufacturing objectives: production of iron powder; of iron-based P/M commodities including self-lubricating, structural and soft magnetic materials and electrode bands; commodities made of refractory metals; friction details made of copper powder and composite commodities.
Iron powder
During the time of its existence, the plant has improved the iron powder-making technology from combined reduction of powdered oxides all the way to atomization of a stream of molten carbon steel with a jet of water and subsequent recovery annealing. At the moment the plant manufactures iron powders that meet the highest standards of foreign customers.
Metal powders manufactured using this technology have a widespread application in various industries, such as:
production of friction, structural and electrotechnical P/M products, sintered electrode bands;
application of metal powders in flux-injection oxygen cutting of metals, as a main component of efficient and nontoxic electrodes;
during flame scaling of metals in iron & steel industry and as nucleating centers in casting of steels;
utilization of powder in preparation of printing dyes, as catalysts and reducing agents in various industrial chemical processes, in magnetic particle inspection and in other applications.
p/M products
Self-lubricating commodities
Along with foundry alloys, such as bronzes, Babbitt metal and irons, modern mechanical engineering uses self-lubricating substances to manufacture slide bearings, bushings, filler inserts and other components. The plant also manufactures self-lubricating P/M articles from iron-graphite, iron-graphite-copper-sulfur, iron-copper alloys, etc.
After the calibration stage, surface roughness comes to some 1.25-1.00, while dimension accuracy complies with the 8th-10th classes of accuracy. Owing to pores that become impregnated with oil, bearings made of P/M products can function in friction unit with limited lubrication. Self-lubricating products can be subject to various machining, such as turning, drilling, broaching and polishing. Application of self-lubricating P/M commodities facilitates economical consumption of scarce metals and alloys, lowers labor intensity and machining efforts, as well as improves the working conditions.
The plant is capable of manufacturing 500 different self-lubricating articles of different shapes, dimensions and purposes.
Structural commodities
These products are widely used in machine building and instrument making. Structural commodities are manufactured as ready-to-use items or semi-finished products, which require insignificant finishing efforts, thus lowering metal losses, easing labor efforts and reducing production costs. For instance, it is 2-2.5 times cheaper to manufacture a tonne of average P/M commodities than to make a tonne of similar rolled or cast products.
The material and the manufacturing technology are selected depending on future application of end commodities. Unstrained and low-strained structural elements are made of pure iron powder and ferrographite. Medium-strained structural products are made of iron-cast iron-chromium, iron-phosphorus-copper, iron-graphite-copper-nickel and chromium-molybdenum powder alloys doped with calcium fluoride. The plant produces component parts for combine harvester’s brakes, impeller oil pumps and sealing inserts for steam turbines. The plant is equipped with automatic presses and heat-treatment facilities capable of manufacturing items with twin passages on the inside and outside, with grooves, protrusions on tips and with various internal apertures.
Soft magnetic materials
The State Powder Metallurgic Plant widely uses soft magnetic substances made of pure iron powder or of phosphorus-added iron powder to manufacture magnetic circuit components for electrotechnics and instrument-making, as well as pole pieces functioning in permanent magnetic fields of various devices and appliances.
Application of soft magnetic P/M products saves electrical steels, lowers labor inputs and metal-cutting efforts.
Sintered electrode bands
These bands are used in efficient, reduction and hardening fusion flux weld deposition of component parts for road-building, metal-making, press-forging and other equipment, as well as for trucks, tractors, bulldozer and grader blades, forming rolls and wheels including continuous caster’s rolls, billets, hydraulic press’s rams, cushioning support, etc.
The bands are manufactured via rolling of mixed metal and ferroalloy powders with subsequent sintering. At present the plant manufactures bands, 1-0.2 mm thick and 40-100 mm wide. Sintered electrode bands are sufficiently strong and flexible. The ultimate strength exceeds 100 megapascals per 10 kg/m2; thus it is possible to use off-the-shelf standard welding and building-up devices in weld deposition processes. During one passage, it is possible to build up a 2.5-3.5 mm-thick weld with width approximately equal to the width of electrode band. Productivity of this method is 2-3 times as high as that of wire weld deposition and 8-15 times as high as that of weld deposition with stick electrodes.
Friction discs
The so-called friction discs are widely used in mechanical clutches of motorcars, tractors and other machinery. Friction discs are manufactured by hot-deposition of friction layers on steel surfaces.
Bronze or brass-based friction substances show good performance under heavy and medium loads in lubricated or non-lubricated frictional environments at surface temperatures below 500-600oC.
The plant manufactures friction discs for T-150 and T-70 tractors, LAZ and LiAZ buses and Balkancar forklift trucks, as well as produces and renovates worn-out friction discs of K-700 tractors.
The plant also uses carbon-reinforced plastic to make friction discs for clutch gear of Voskhod, Courier, Sova and Minsk motorbikes. These discs operate in lubricated mediums under heavy and medium loads. The coefficient of friction in oil comes to 0.08, while thickness wear after a 12,000 km mileage equals 0.04-0.08 mm.
HIGH-MELTING-POINT MATERIALS
The plant has mastered production of over 100 types of such products made of cemented silicon carbide, titanium carbide and titanium boride powders.
Items made of cemented silicon carbide
The process of manufacturing these products comprises compounding of semis and subsequent chemical sintering in fused electrolyte or in silicon fumes.
Such commodities can easily by polished with diamond tools to meet the required precision and surface finish standards. Besides, they can be applied in environments with intensive abrasive and hydroabrasive damage. Application of cemented silicon carbide in grates of papermaking machines doubles the service life of grates. Chemical industry uses wear-resistant linings and spray jet nozzles made of cemented carbide with serviceability for 800-1,000 hours of continuous operations.
Drawing cable-making mills apply cemented silicon carbide as a material for draw rolls with service life sixfold as long as that of rolls made of ShH-15 steel. Products made of cemented silicon carbide have found widespread application as die components in hot die-casting of ferrites, electroceramics and piezoceramics under temperatures of up to 1,300oC and pressure of up to 500 kg/cm2. All the other metallic and ceramic materials simply fail to function in such extreme conditions.
The State Powder Metallurgic Plant manufactures lining for hydro-cyclones and soil pumps using silicon carbide-based substances (the so-called MPK material) as liners. Linings for hydro-cyclones, 150 mm, 360 mm, 500 mm and 710 mm in diameter, are to protect cyclone bodies from hydro-abrasive effect of ferrous and nonferrous ores, concentrating coals, as well as from exposure to sands when drilling oil and gas boreholes.
Service life of such hydro-cyclone linings amounts to 10-15 years, which is 20 times as high as serviceability of lining made of cast stones or wear-resistant rubber. Service life of soil pump linings is sixfold or even eightfold greater than that of the previously applied Bakelite-bonded electrocorundum, chromium-nickel irons and rubbers.
Silicon carbide shrouds for thermocouples are applied in continuous taking of temperature in molten aluminum and aluminum alloys, nonferrous metals, as well as in oxidizing mediums at temperatures of 1,300oC.
These shrouds have an average service life of up to 750 hours in molten aluminum at the temperature of 700oC and up to 2,000 hours in air environment at the temperature of 1,000oC.
Articles made of DTKT substance
The DTKT substance (titanium diboride + titanium carbide) is applied as evaporative agent in vacuum deposition units that plate metals, glass, film, paper, fabrics and other materials with aluminum and other metallic coats. Crucibles, drawbars, arbors and other items are manufactured from this material. Evaporative agents have a service life of 2-3 hours depending on the heating method and metallization mode.
The plant has also invented a technology of making scale hydro-knocking nozzles of the DTKT material. Such nozzles are applied in hot rolling of ferrous metals and have a 5-6 time longer service life than nozzles made of X13M steel.
Composites
Collapse of the Soviet Union and conversion of defense industries have truly pushed down the demands for composite materials. As a matter of fact, consumption of the latter practically discontinued. Thus, the plant had to re-target its production plans and to use state-of-the-art equipment to manufacture ordinary goods, such as carbon-reinforced resins, fiberglass-reinforced plastics, various packings, etc.
Carbon packing
This packing is a cord woven from carbon threads impregnated with organic silicon polymers, from 8×8 mm to 24×24 mm in cross section. The cord has the following properties:
enhanced thermal and thermal-oxidation stability of organic silicon compounds, negligible dependence of viscosity on temperature, as well as chemical, hydrolytic and biological inertia;
high compressibility and nice frictionless performance;
environmental safety and fireproof qualities.
Carbon packing is applied in pumps and various watertight and steam-tight regulating accessories under pressure of up to 20 megapascals and temperatures from 2oC to 150-300oC (depending on the medium).
Service life of this type of packing is 15-20 times as long as the life span of hemp and asbestos packings.
Hemp packing
This kind of packing is a cord made of woven flax-hemp twine soaked in organic silicon polymers or oil, from 8×8 mm to 24×24 mm in round or square cross section. Hemp packing is widely applied in power engineering, chemical industry, petrochemical industry, food processing, public services, etc. Owing to unique properties of impregnating solutions, hemp packing has a better serviceability in both static and dynamic environments than other graphite packings. All these qualities ensure lengthy durability, flexibility, nondrying qualities and stable physical and chemical properties over a long service period.
The plant holds the permit issued by the Ukraine’s Ministry of Health Care to use hemp packing in contact with drinking water.
Hemp packing is used in pumps and stuffing boxes working in water and steam mediums, oil products, etc.
Fiber composites
Besides to manufacturing the renowned fiber laminates, fiberglass-reinforced plastics and Gethinax, the plant also produces a new self-lubricating composite material tribolite. The new tribolite is applied in components and friction units operating under limited lubricant feed and high vibration, as well as in impure mechanisms.
This material features a coefficient of friction coming to 0.03-1.5, density of 1.3-1.4 g/cm3, breaking point in strain perpendicular to layers of at least 130 megapascals.
Perhaps, the most wearing parts of widely used vacuum rotary impeller pumps are the fiber-reinforced impeller blades (fins). The State Power Metallurgic Plant manufactures these impeller blades of tribolite with enhanced self-lubricating properties. The plant has at dispose all the necessary facilities and produces such impellers for vacuum rotary pumps applied in group and individual milking, for pumps used in printing, for compressors of cement and flour carriers, etc.
Service life of these blades amounts to at least 1,000 hours under 0.04-0.15 coefficient of friction.
Upon request of our clients, the plant can manufacture impeller blades, up to 0.5 m long, to fit all the possible types of vacuum units or compressors.
Absorbent filters
At this point of time, these substances attract strong interest all around the world as efficient materials assisting in solution of technical and pollution-control problems.
Since 1988 the plant has been mass-producing AUVM DNEPR-MN, an activated carbon fiber-reinforced absorbent for technical and medical purposes, which excels simple activated carbons and other absorbents. This substance is used to manufacture multilayer filters for liquids and gases with low flow resistance, thus enabling utilization of low-pressure superchargers.
AUVM DNEPR-MN material has a great hemostatic and bacteriostatic effect and high capillary hygroscopicity, which is 3-3.5 times as great as hygroscopic properties of ordinary gauze.
This substance is used as dressing for prophylaxis of purulent-septic complications, medical treatment of infected wounds, burns of various degrees and areas exposed, exudative eczemas and peptic ulcers.
Owing to high strength and elasticity, this material closely fits surface of wounds of any shape. This substance causes no local irritation or allergic side effects and is advised for application in general and burns surgery, traumatic surgery, obstetrics, gynecology, proctology and dentistry.
This material facilitates stoppage of wound bleeding and mixing of edemata, speeds up regeneration and reparation, as well as accelerates cicatrization of wounds 1.5-2 times.
Nonstandard equipment
There was an urgent need in creation of new and nonstandard equipment, such as sintering furnaces, die-casting units, press tools, etc., to meet specific requirements of powder metallurgy. Resolving this problem, the plant has brought together a powerful team of designers and highly skilled toolmakers. Due to a notorious recession in output, the issue of retaining this team has become paramount. The plant’s management had to find a proper application for potential of these specialists.
Therefore, the team faced a task to work out engineering documents and manufacture VVU-1 and NVVU-2-type oscillating diggers to harvest sugar beet. Such diggers would have to apply a special design of plowshare different from the mass-produced roller and disc machines. This allowed lowering beet losses to the absolute minimum of 3% owing to:
harvesting of sugar beet without damaging the roots, including gathering from the ground’s surface;
effective harvesting operations on weed-infested fields;
when gleaning roots, the digger aligns itself within the range of 50 mm to the left or to the right of the row.
VVU-1 oscillating diggers are easily installed on KS-6B and similar beet combine harvesters, while VVU-2 diggers equip RKM-6 harvesters. Both types of diggers showed nice performance during the 1996-1998 harvesting seasons in Khmelnitsky, Zhitomir, Kiev, Kharkov, Poltava and Cherkassy regions. Both diggers were certified by the Ukrainian State Center for Manufacturing and Forecasting of Agricultural Machinery UkrCVT.
Naturally, the plant faced difficult financial times brought about by the forced reduction in output of principal products. The plant struggles for existence and takes all the necessary steps to retain productive facilities, main teams of engineers and workers, as well as makes all the efforts to stay among the leaders of scientific and technological progress.
the Metal