Improved weldability diagram for pulsed laser welded austenitic stainless steels
Tóm tắt
Pulsed Nd:YAG laser welds were produced on 23 different austenitic stainless steel alloys of known composition. The primary solidification mode (PSM) and solidification cracking susceptibility of individual welds on each alloy were identified and correlated with their compositions. Single phase austenite solidification occurred in alloys with Cr equivalent to Ni equivalent ratios (Creq/Nieq) below approximately 1.59 (Hammar and Svennson equivalency relations). Alloys having a Creq/Nieq value above approximately 1.69 exhibited single phase ferrite PSM, whereas alloys for which Creq/Nieq was between 1.59 and 1.69 displayed either single phase ferrite PSM or a dual PSM with grains of single phase austenite adjacent to grains of single phase ferrite. The results of the present work were combined with those of a previous study to construct an improved weldability diagram for pulsed Nd:YAG laser welding of austenitic stainless steels. Consistent with previous observations, alloys that solidified as primary austenite were more prone to solidification cracking. Alloys that solidified as austenite (Creq/Nieq < 1.59) generally cracked when the combined impurity content (P + S) was greater than approximately 0.02%. However, cracking was not found in alloys that solidified as primary austenite with combined impurity content less than approximately 0.02%. Solidification cracking behaviour of alloys that solidified in a dual mode (1.59 < Creq/Nieq < 1.69) appeared to vary with impurity content. No cracking was observed in any of the alloys that solidified as primary ferrite (Creq/Nieq > 1.59).
Từ khóa
Tài liệu tham khảo
Fuerschbach P. W.: Proc. Conf. on ‘Power beam processing’, 157–164; 1988, Materials Park, OH, ASM International.
Fuerschbach P. W., 1997, Weld. J, 76, 103s
Arata Y., 1976, Trans. JWRI, 5, 35
Arata Y., 1977, Trans. JWRI, 6, 105
Brooks J. A., 1978, Weld. J, 57, 139s
Savageand W. F., 1965, Weld. J, 44, 433s
Schaeffler A. L., 1947, Weld. J, 26, 601s
Schaeffler A. L., 1949, Met. Progr, 680B
Delong W. T., 1956, Weld. J, 35, 526s
Long C. J., 1973, Weld. J, 52, 281s
Hull F. C., 1973, Weld. J, 52, 193s
Hammar O., and Svensson U.: Proc. Conf. on ‘Solidification and casting of metals’, Sheffield, UK, July 1980, The Metals Society, 401–410.
Espy R. H., 1983, Weld. J, 61, 149s
Siewert T. A., 1988, Weld. J, 67, 289s
Kotecki D. J., 1992, Weld. J, 71, 171s
Suutala N., and Moisio T., Acta Universitatis Ouluensis (1982) C23 (Metallurgica 3), 1–11.
David S. A., 1979, Weld. J, 58, 330s
Leone G. L., 1982, Weld. J, 21s
Kujanpää V., 1979, Weld. Res. Int, 9, 55
Kujanpää V., 1980, Met. Constr, 12, 282
Kujanpää V., and Moisio T.: Proc. Conf. on ‘Solidification technology in the foundry and casthouse’, Coventry, UK, September 1980, The Metals Society, Session IVb.
Katayama S., and Matsunawa A.: Proc. Conf ‘ICALEO 1984’, Boston, MA, USA, November 1984, Laser Institute of America, 60–67.
Katayama S., and Matsunawa A.: Proc. Conf ‘ICALEO 1985’, San Francisco, CA, USA, November 1985, Laser Institute of America, 19–25.
Lippold J. C., 1985, Weld. J, 64, 127s
David S. A., 1987, Weld. J, 66, 289s
Brooks J. A., and Baskes M. I.: Proc. Conf on ‘Recent trends in welding science and technology’, Gatlinburg, TN, USA, May 1989, ASM International, 153–158.
Elmer J. W. ‘The influence of cooling rate on the microstructure of stainless steel alloys’, ScD dissertation, Massachusetts Institute of Technology, Cambridge, MA, USA, 1988.
Kurz W., and Trivedi R.: Proc. Conf. on ‘Trends in welding research’, Gatlinburg, TN, USA, June 1995, ASM International, 115–120.
Nakao Y., 1988, Trans. Jpn Weld. Soc, 19, 20
Pacary G., Moline M., and Lippold J. C. ‘A diagram for predicting the weld solidification cracking susceptibility of pulsed-laser welds in austenitic stainless steels’, EWI Research Brief No. B9008, Edison Welding Institute, Columbus, OH, USA, 1990.
Brooks J. A., and Lippold J. C.: in ‘Welding brazing and soldering’, ASM Handbook Vol. 6, (ed. D. L. Olson et al.), 456–470; 1993, Materials Park, OH, ASM International.
Lippold J. C., 1994, Weld. J, 73, 129s
Rosenthal D., 1941, Weld. J, 20, 220s
Adams C. M., 1958, Weld. J, 37, 210s
Flemlngs M. C.: in ‘Solidification processing’, 147–154; 1974, New York, McGraw-Hill.
Yardy J. W., and Laursen B. N.: Proc. Conf. on ‘Trends in welding research’, Gatlinburg, TN, USA, June 1995, ASM International, 165–170.
Fontana M. G.: in ‘Corrosion engineering’, 74–76; 1986, New York, McGraw-Hill.
‘Standard methods for estimating the average grain size of metals’, Standard E112–63, part 31, ASTM, Philadelphia, PA, 1963, 225–239.
Goodwin G. M., 1987, Weld. J, 66, 33s