Association of microstructural features and rippling phenomenon in 304 stainless steel gas tungsten arc welds

Abstract

High speed, high magnification video microscopy has been used to investigate rippling behaviour in autogenous 304 stainless steel gas tungsten arc (GTA) welds. Images of the trailing edge of a weld pool (solid-liquid interface) were collected during the welding process. Weld ripple formation was observed and the associated solid-liquid interface velocity was measured. A distinct sequence of events was observed each time a ripple formed. This sequence of events involved apparent changes in the solid-liquid interface velocity, dendrite morphology, and dendrite growth direction. The microstructures of a group of rippled welds were examined and a number of features associated with the rippling phenomenon were identified. These features included changes in the pattern of the interdendritic constituents and changes in the solute distribution across the ripple feature. This information coupled with the video images was used to explain more fully the weld rippling phenomenon and the origins of microstructural changes associated with it. It is shown that solute redistribution occurs in the weld on a length scale associated with the ripple features.

Keywords

GAS TUNGSTEN ARC GTA WELD RIPPLING SOLIDIFICATION SEGREGATION SOLUTE REJECTION WELD POOL OSCILLATION SOLUTE PARTITIONING SOLUTE REDISTRIBUTION FE-NI-CR STAINLESS STEEL

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References

Aendenroomer

A. J. R.

and Den Ouden

: Weld. J, 1998, 77, (5), S181–S187.

Andersen

, Cook

G. E.

, Barnett

R. J.

and Strauss

A. M.

: IEEE Trans. indust. Appl., 1997, 33, (2), 464–471.

Wei

P. S.

, Chang

C. Y.

and Chen

C. T.

: J. Heat Transfer (Trans. ASME), 1996, 118, (4), 960–969.

Ecer

G. M.

, Gokhale

and Brody

H. D.

: J. Met., 1980, 32, (8), 80.

Kotecki

D. J.

, Cheever

D. L.

and Howden

D. G.

: Weld. Res., August 1972, 386s–391s.

Postacioglu

, Kapadia

and Dowden

: J. Phys. D, Appl. Phys, 1991, 24, (8), 1288–1292.

Morvan

and Bournot

: int. J. Numer. Meth. Heat Fluid Flow, 1996. 6, 13–20.

Mazumder

: Opt. Eng., 1991, 30, (8), 1208–1219.

D'annessa

A. T.

: Weld. Res., February 1970, 41s–45s.

10.

Garland

J. G.

and Davies

G. J.

: Met. Constr. Br. Weld. J., May 1970, 171–175.

11.

Lin

M. L.

and Eagar

T. W.

: Proc. Conf. ‘Transport phenomena in materials processing’, (ed. M. M. Chen et al.), ASME Publication PED Vol. 10, HTD Vol. 39, 63–69; 1983, New York, USA, American Society of Mechanical Engineers.

12.

Nemchinsky

V. A.

: int. J. Heat Mass Transfer, 1997, 40, (4), 881–891.

13.

Morvan

and Bournot

: Proc. SPIE, 1995, 2502, 643–649.

14.

Schwartz

A. J.

and Adams

B. L.

(eds.): ‘Electron backscatter diffraction in materials science’; 2000, New York, Kluwer Academic/Plenum Publishers.

15.

Kurz

and Fisher

D. J.

: in ‘Fundamentals of solidification’, 3rd edn, Vol. 3, 305; 1992, Aedermannsdorf, Switzerland, Trans Tech Publications.

16.

Elmer

J. W.

: ‘The influence of cooling rate on the microstructure of stainless steel alloys’, PhD thesis, Department of Materials Science and Engineering, Massachusetts institute of Technology, Cambridge, MA, USA, 1988, 388.