摘要:
A main electrode (2, 20, 30, 44, 127) for plasma arc generator, a generator (50, 70, 80, 126) comprising same and a process for treatment of solidifying liquid metal by the mentioned generator, wherein the main electrode in association with a counter electrode (15, 28, 42, 54, 73, 86, 122) provides a two-rail structure capable of generating a plasma arc discharge displaceable along a closed path uninterruptedly. The uninterrupted movement of the arc discharge is achieved by a specific design of the main electrode. The electrode comprises an essentially tubular body having a first rim (3, 24, 33, 89) usually connected to a d.c. power source via at least one connector site (12), and a second, working rim (4, 27, 34, 46, 63, 78, 90) serving for the electric arc discharge. The tubular body is divided by at least one slot (gap) (6, 22, 32, 49, 52, 88) associated with one connector site and extending between the first and second rims so that it forms at the second rim region a second rim gap. Two sides of the second rim gap are an arc transmitting (16, 36) and an arc receiving (17, 35) zones, respectively. Mutual positions of these two zones and the associated connector site are such, that when the arc column is created and displaces along the second rim, it will always be transmitted from the transmitting zone to the receiving zone at a location positioned downstream from the projection of the associated connector site to the second rim (in respect of the direction of the plasma arc movement). Owing to this arrangement the arc column will cross the second rim gaps uninterruptedly.
摘要:
A method and apparatus for stirring and treating continuous and semi-continuous casting of metallic rods (12). The apparatus comprising: a stand (30) for suspending at least one electric arc electrode (24) over the upper surface of a metallic casting (14) after or during pouring, at least one electrode (24) for forming a moving electric arc (38) over the upper surface of the mettalic casting being cast, a second electrode, being the liquid metal (14), for completion of an electric circuit including said electric arc (38) and the liquid metal (14); and control means (34), connected between said apparatus and a power supply (36) and arranged to supply power to the plasma arc electrodes (14, 24), for monitoring the parameters of the electric arc (38). The invention also provides a method for casting the metallic rods (12) by using the above described apparatus.
摘要:
An apparatus (10) and a method for reducing inclusions, shrinkage blowholes, porosity and segregation in metal castings during the casting process, and for improving the grain structure, mechanical properties and yield of ingots and other castings. The apparatus (10) comprises: At least one electrode (14) for forming a moving electric arc (16) over the upper surface (18) of a metallic casting (12) being cast and a stand (20) for suspending the electric arc electrode (14) over the upper surface (18) of the metallic casting (12) during or after pouring and a second electrode (24) attachable to a metallic surface (26) of the mold (28) being used for casting, for completion of an electric circuit (30) including the electric arc (16) and electronic controls (32) connected between the apparatus (10) and a power supply (34).
摘要:
An apparatus (10) and a method for reducing inclusions, shrinkage blowholes, porosity and segregation in metal castings during the casting process, and for improving the grain structure, mechanical properties and yield of ingots and other castings. The apparatus (10) comprises: At least one electrode (14) for forming a moving electric arc (16) over the upper surface (18) of a metallic casting (12) being cast and a stand (20) for suspending the electric arc electrode (14) over the upper surface (18) of the metallic casting (12) during or after pouring and a second electrode (24) attachable to a metallic surface (26) of the mold (28) being used for casting, for completion of an electric circuit (30) including the electric arc (16) and electronic controls (32) connected between the apparatus (10) and a power supply (34).