METHOD OF WELDING OF DEFECTS IN ALUMINIUM ALLOY CASTINGS Russian patent published in 1998 - IPC

FIELD: ship board mechanical engineering. SUBSTANCE: proposed method may be used to correct defects in castings by welding for alloys based on aluminium, marks AЛ2,AЛ 4,AЛ4B,AЛ9,AЛ11,AЛ8,AЛ13,AЛ23-1,AЛ-28. In this case, manual argon-arc welding can be used. Prior to welding, castings are heated up to temperature of 340-380 C for alloys of aluminium, marks AЛ8,AЛ13,AЛ28,AЛ,AЛ-23-1,, up to 250-300 C for marks AЛ2,AЛ4,AЛ4B,AЛ9 and up to 280-300 C for marks AЛ11. Heating is checked by thermopencil or contact thermocouple. Ultrasonic oscillations are excited in material at frequency close to frequency of casting material inherent oscillations. Welding is performed by short arc. Surfacing is carried out by means of facing rollers not more than 15-18 mm wide. Beginning and end of roller do not coincide with preceding roller end. In welding, continuous transitions between rollers and from seam to basic metal are provided. After welding to the entire depth fused-on surface and adjacent zone of basic metal are cleaned of splashes. Checking is performed by external inspection and measuring the velocities of spreading of ultrasonic longitudinal and transverse waves before and after welding. Revealed defects are eliminated. Technology described above improves casting quality, reduces power consumption of process and raises process efficiency, as compared with traditional classic methods of welding the casting defects. EFFECT: prevention of crack formation. 7 cl, 4 tbl, 1 dwg