Accession Number : AD0746886

Title :   Formation of the Weld Deposit and Its Effect on the All-Weld-Metal Heat-Affected-Zone,

Corporate Author : LEHIGH UNIV BETHLEHEM PA FRITZ ENGINEERING LAB

Personal Author(s) : Perle,Morton M.

Report Date : JUL 1972

Pagination or Media Count : 220

Abstract : The three-dimensional shape of a gas metal-arc weld puddle was graphically constructed using a centerline section of a hammer decanted weld, a weld cross-section and the top surface crater outline of the weld puddle. Velocities of melting and solidification were computed at every point within the weld puddle. The analysis showed that the weld papillary region typically solidified 19 times as fast as the trailing portions of the weld puddle and that the arc jet effect causes papillary penetration. Lateral melting of the weld bead is caused by liquid circulation. Etching with sodium bisulfite solutions revealed patterns of weld solidification segregation. Microprobe study showed that these patterns were evidences of segregation of nickel, manganese, silicon and molybdenum in the last interdendritic liquid to solidify. The forms of solidification structure change from cellular to columnar dendrites with decreasing solidification velocity. (Author)

Descriptors :   (*WELDS, RELIABILITY), (*INERT GAS WELDING, *DEPOSITS), WELDING, DEPOSITION, MICROSTRUCTURE, PHASE STUDIES, AUSTENITE, MATHEMATICAL MODELS

Subject Categories : Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE