Metal Science and Heat Treatment

Cherdantsev, A.; Makar'ev, A.; Akhant'ev, V.; Kaplina, I.

doi: 10.1007/BF01158069pmid: N/A

The valve gas-distributing mechanism is an important part of an internal combustion engine. Its main components are inlet and discharge valves, which have to meet specific requirements due to the conditions of their operation. The general requirement on all valves is their close fitting to the seats under a high pressure in the cylinder, which is realized due to the conical camfer that serves as the seat surface. For this reason, the camfers are ground thoroughly. The rod of the valve, which moves inside a guide bush, is also fabricated with high precision. The valves operate at an elevated temperature and therefore are produced from high-temperature alloys. The present paper is devoted to the manufacturing technology for valves of the gas-distributing mechanism.

Kudryashov, G.

doi: 10.1007/BF01158070pmid: N/A

The use of protected small-sized frequency converters for heating parts for hardening in combination with various quenching apparatuses designed for specific parts makes it possible to conduct heat treatment directly on the technological lines of the mechanical shops with a full production cycle. This envisages a high level of mechanization up to complete automation and the shortest production cycle without creating large interoperational reserves. The experience in the practice of induction heating in heat treatment of automobile parts is generalized.

Tikhonov, A.; Bogdanova, N.

doi: 10.1007/BF01158071pmid: N/A

Gas nitriding in partially dissociated ammonia is widely used in machine building. Surface layers obtained by this method consist of continuous nitrides and are characterized by high brittleness and susceptibility to scoring and spalling in operation. The processes of short-duration gas nitriding in a mixture of ammonia and exogenic gas used by the VAZ plant provide surface layers that are more plastic than nitride, carbonitride, and oxynitride layers. The chemical reactions occurring in this process are analyzed and the equilibrium composition of the exogenic gas is calculated.

Kochergin, A.; Ridosh, B.

doi: 10.1007/BF01158072pmid: N/A

Modern technology uses a large number of gears of different standard sizes. The automobile industry is the largest producer of gears. Volzhskii Automobile Plant produces transmission gears, back-axle reduction gears, and front-drive gears on a mass scale. The present paper is devoted to the technological processes of chemical heat treatment (CHT) of gears and the methods for controlling the furnace atmosphere and the quality of parts.

Koftelev, V.; Rudenko, E.

doi: 10.1007/BF01158073pmid: N/A

Every car of the Volzhskii Automobile Plant consists of 1.6 (VAZ-2106) to 4.0 (VAZ-2110) kilograms of parts fabricated from powder materials. By the middle of 1996 the range of these parts (weighing from 1.5 to 600 g) consisted of 150 items. They are fabricated from powders based on iron and copper (119 and 31 items, respectively). Almost half of the iron-base powder parts are subjected to various kinds of surface treatment, namely, carburizing, cyaniding, gas nitriding, and steam oxide treatment. The present paper is devoted to the special features of chemical heat treatment (CHT) of parts produced from iron (steel) powder materials.

Kitaigora, N.

doi: 10.1007/BF01158074pmid: N/A

Methods for solving problems arising in the production of high-strength cast iron with stable properties and structure are considered. Results of introduction of new grades of high-strength cast iron instead of malleable cast iron and camshaft cast iron in the Volzhskii Automobile Plant are described.

Ivanov, A.; Tsaplina, N.; Kablov, V.

doi: 10.1007/BF01158075pmid: N/A

A brief description of the technology of piston ring castings made of gray cast iron with spheroidal graphite is presented. Special attention is paid to the melting regimes and modification of the melt as the most important factors that determine the structure and properties of the metal in the cast preforms. Methods for controlling the quality of the preforms are considered.

Chernyshev, A.; Kaplina, I.; Serapin, M.

doi: 10.1007/BF01158076pmid: N/A

The most important requirements on engines of passenger cars include a low specific consumption of fuel, which depends on the process of the gas distribution controlled mechanically with the help of the camshaft. In operation, camshafts are subjected to rolling friction with elements of slip. Wear is mainly developed at the top of the cams, causing a change in the design contour. This worsens the operating regime of the gas-distributing mechanism and, correspondingly, the characteristics of the engine. At present, the processes of gas distribution in the engine are optimized using cams with a sharpened profile and a long stroke, with accelerates their wear. This stimulates a search for new methods of increasing the wear resistance of the cam-pusher pair.