THERMIT WELDING METHOD Russian patent published in 2001 - IPC

FIELD: metal welding by fusion, namely thermit welding, possibly for butt welding of vertically arranged tubes. SUBSTANCE: method comprises steps of preliminarily pressing thermit composition in the form of two ring halves; placing them in welding cavity of refractory form over butt zone of welded portions of tubes while forming annular cavity between tubes and ring halves; igniting thermit composition in lower portion of ring halves; using as metal oxides in thermit composition oxides of copper, nickel, ferrum, cobalt, molybdenum or oxide concentrate of those metals; using as reduction agent boron or lamp black or metal selected from group containing aluminum, magnesium, silicium or silicides of calcium, ferrum and(or) titanium or carbides of boron and silicium; using as slag forming additives alkali metal carbonates, tetraborates or nitrates or their mixture. Method provides welding and soldering of tubes in hard-to- reach places and possibility for making high quality joint independently upon qualification degree and skill of operator. EFFECT: high quality welded joints of tubes. 1 dwg