Abstract: The work-performing member for a farm machine has a cutting edge made of a high-carbon steel containing graphite in structurally free state in an amount of 0.5 to 1.32 percent of the total mass of the material.

Abstract: A torch for gas-shielded arc welding in a deep narrow groove comprises a current contact torch bit (1) with an electrode (2) and a nozzle for supplying the shielding gas to the welding zone, which communicates with a gas-feeding tube (4) and is provided with at least one row of horizontally arranged holes (5). The nozzle is a closed chamber (3) made as a symmetrical wedge whose sharp edge faces the electrode (2) and is in one plane with the axis thereof. The side walls and bottom of the chamber (3) feature at least one additional row of holes (6) whose axes lie in one plane approximately perpendicular to the walls (7) of the groove.The torch is designed primarily for welding of very thick workpieces.

Abstract: An apparatus for gas-shielded arc welding comprises a mechanism (1) for guiding and feeding an electrode to a welding zone (3), a nozzle (4) for feeding a protective gas medium to the welding zone (3) and a TV transmission camera (6) for realtime monitoring of the welding process. A cover plate (8) made of an optically transparent material is provided at the end (7) of the gas nozzle (4) which is remote from the welding zone (3), and a lens (9) of the TV camera (6) is installed above the cover plate (8) coaxially therewith. The distance ("a") from the cover plate (8) to the lens (9) is selected in such a manner that the zone (3) of sharpness of the lens is located beyond the edge (11) of the gas nozzle (4) which is adjacent to the welding zone (10) and extends over the components of the welding process.An apparatus for gas-shielded arc welding is designed preferably for welding thick plate materials, for example, pressure vessel casings.

Abstract: The burner for metallurgical furnaces comprises a main combustion chamber (7) and an auxiliary combustion chamber (5) presenting a plurality of outlet channels (6) communicating with the main combustion chamber (7). To the main combustion chamber there is fed in a pulsating manner a primary mix of fuel gas and air in stoichiometric ratio, and, during the intervals between the feed pulses, a secondary mix of fuel gas and air with a coefficient of excess air of 1.15 to 1.35 and at a rate of flow corresponding to 1 to 3% of the nominal rate of flow. To the auxiliary combustion chamber (5) there is instead continuously fed an auxiliary mix of fuel gas and air with a coefficient of excess air of 0.65 to 0.85 and at a rate of flow corresponding to 1 to 3% of the rate of flow of the primary mix. The combustion products of the auxiliary mix stay in the auxiliary combustion chamber (5) for a very short time, more particularly for about from 0.005 to 0.01 sec.