Role of filler alloy composition on laser arc hybrid weldability of nickel-base IN738 superalloy

Abstract

Laser arc hybrid weldability study was performed on nickel-base IN738 superalloy using nickel-base filler alloys of various compositions. Propensity for heat affected zone (HAZ) intergranular liquation cracking in the weldments was observed to vary depending on the Al+Ti+Nb+Ta concentration of the weld metals produced by the different filler alloys. Detailed study, including SEM and TEM analyses, thermodynamic calculations and microhardness evaluation revealed that variation in HAZ cracking susceptibility of IN738 superalloy when different filler alloys are used during laser arc hybrid welding can be attributed to variation in the extent of precipitation hardening produced in the weld metals. Additionally, shrinkage, and the consequent volumetric changes, due to γ′ precipitation in the weld metals could have contributed to excessive tensile loading of the crack susceptible HAZ and aided intergranular liquation cracking.

Keywords

Laser hybrid HAZ cracking Filler alloy Precipitation hardening Volumetric change

Get full access to this article

View all access options for this article.

References

Yang

, Gebelin

J.-C

and Reed

: Mater. Sci. Technol. , 2011, 27, 1249–1264.

Jiang

, Li

, Wang

and Zhang

: Mater. Sci. Technol. , 2011, 27, 1385–1390.

Osoba

and Ojo

: Mater. Sci. Technol. , 2012, 28, 431–436.

Prager

and Shira

: Weld. Res. Council Bull. , 1968, 128, 1–55.

Thakur

, Richards

and Chaturvedi

: Int. J. Join. Mater. , 2003, 15, 21–25.

Sims

, Stoloff

and Hagel (eds.)

: ‘Superalloys II: High Temperature Materials for Aerospace and Industrial Power’, 3; 1987, A Wiley-Interscience publication.

Ojo

, Richards

and Chaturvedi

: Mater. Sci. Technol. , 2004, 20, 1021–1034.

Antony

and Goward

: in ‘Superalloys 1988’, (ed. Reichman

et al.), 745–754; 1988, Warrendale, PA, The Metallurgical Society.

Steen

and Eboo

: Metal Constr. , 1979, 7, 332–335.

10.

Ribic

, Plamer

and DebRoy

: Int. Mater. Rev. , 2009, 54, 223–244.

11.

Bagger

and Olsen

: J. Laser Appl. , 2005, 17, 2–14.

12.

Staufer

: Weld. J. , 2007, 86, 36–40.

13.

Mahrle

and Beyer

: J. Laser Appl. , 2006, 18, 169–180.

14.

Ishide

, Tsubota

, Watanabe

and Ueshiro

: J. Jpn Weld. Soc. , 2003, 72, 22–26.

15.

Ola

, Ojo

and Chaturvedi

: Mater. Sci. Technol. , 2013, 29, (4), 426–438

16.

Saunders

, Li

, Miodownik

and Schille

JPh

: Proc. Symp. on ‘Materials design approaches and experiences’, (ed. Shao

J-C

et al.), 185–197; 2001, Warrendale, PA, TMS.

17.

Ojo

, Richards

and Chaturvedi

: Metall. Mater. Trans. A , 2006, 37A, 421–433.

18.

Shinozaki

and Kuroki

: Weld. Int. , 2000, 13, (12), 1–9.

19.

Lippold

: Weld. J. , 1983, 62, (1), 1–11.

20.

Davis JR : ‘ASM specialty handbook – nickel, cobalt and alloys’, 267; 2000, Materials Park, OH, ASM International.

21.

and Wang

: J. Mater. Eng. Perform. , 2010, 19, 1362–1369.

22.

Okubo

and Uryu

: Weld. Int. , 1996, 10, (4), 274–281.

23.

Rosenthal

and West

DRF

: Mater. Sci. Technol. , 1999, 15, 1387–1394.

24.

Pike

: ‘Superalloys 2008’, 191–200; 2008, Warrendale, PA, TMS.

25.

Ross

and Sims

: ‘Nickel-base alloys’, in ‘Superalloys II: high temperature materials for aerospace and industrial power’, 97–133; 1987, New York, NY, Wiley-Interscience.

26.

Ravindran

and Chaturvedi

: Metall. Trans. A , 1975, 6A, (1), 213–217.

27.

Banerjee

, Richards

and Chaturvedi

: Metall. Mater. Trans. A , 2005, 36A, 1881–1890.

28.

Demyantsevich

: Weld. Product. , 1969, 14, (3), 1–6.

29.

Ojo

and Chaturvedi

: Mater. Sci. Eng. A , 2005, A403, 77–87.

30.

Fragomeni

: Recent Adv. Solids Struct. , 1999, 398, 179–194.

31.

Reppich

, Schepp

and Wehner

: Acta Metall., 1982, 30, 95–104.

32.

Nembach

, Schanzer

, Schroer

and Trinckauf

: Acta Metall. , 1988, 36, (6), 1471–1479.

33.

Ardell

: Metall. Trans. A , 1985, 16A, 2131–2165.

34.

Chase

: ‘High-temperature properties of welded cast Co-base alloys’, Proc. 2nd Int. Conf., Champion, PA, USA, September 1972, The Metallurgical Society AIME, Seven Springs Mountain Resort, R1–R23.

35.

Gitgarts

, Tolstoy

and Ivashin

: Fiz. Metal. Metalloved , 1972, 33, (4), 820–823.