Anyagtudomány és Technológia Tanszék
MIG-welding and MIG-brazing of different austenitic stainless steel sheets Eszter KALÁCSKA, Balázs VARBAI, Kornél MÁJLINGER 29th
[email protected]
International Welding Conference
Miskolc, 24-26th May, 2018.
Classification of stainless steels • • • •
Four corrosion resistant types (microstructure) Austenitic → 75% Fluctuation of Ni price HSS- High Strength Steel
Stainless Steels - Introduction To The Grades And Families https://www.azom.com/article.aspx?ArticleID=470 Nickel Prices Forecast: Long Term 2017 to 2030 https://knoema.com/ydolvrc/nickel-prices-forecast-long-term-2017-to-2030-data-and-charts
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Base materials – chemical composition
• Sheets: 2.28 mm, 1.92 mm, 2 mm, 2 mm • PMI Master Sort emission spectrometer Mat. number (AISI) 1.4371 (≈201) 1.4376 (≈200) 1.4318 (301) 1.4301 (304) 1.4316 (308) 2.0922 (braz.)
C 0.05 0.11 0.05 0.05 0.02 -
Chemical composition (wt%) Cr Ni Mn Si Mo Cu N 15.8 4.4 7.7 0.5 0.1 0.4 0.2 17.1 3.8 7.2 0.6 - 0.5 0.2 16.5 7.3 1.6 0.5 0.2 0.3 0.2 18.3 8.6 1.8 0.4 0.2 0.4 19.0 9.5 1.8 0.9 - 0.3 0.2 0.05 - bal. -
Al 8
Fe bal. bal. bal. bal. bal. 0.1 3
Base materials – mechanical properties
Mat. number (AISI) 1.4371 (≈201) 1.4376 (H400) 1.4318 (301) 1.4301 (304) 1.4316 (308) 2.0922 (braz.)
Main properties Rp0.2 Rm A11.3 Hardness Grain size (MPa) (MPa) (%) (HV0.5) (µm) 620 760 25 277±10 12 405 740 40 251±10 11 350 660 35 205±2 10 190 620 35 187±5 22 390 590 35 195±4 175 420 40 165±6 -
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Welding tests • Steel sheets • 130x60 mm • No edge champfering • Thickness step: face side
• Welding machines • MIG: ESAB LUD 450 • MIG-brazing: Fronius Transpuls Synergy2700 TIG
Májlinger K., Kalácska E., Spena P. R.: Gas metal arc welding of dissimilar AHSS sheets, Materials and Design, 2016, 109. p. 615-621
• Shielding gas • MIG: Ar 4.6, both face and root, 10 and 8 l∙min-1 • MIG-brazing: Aluline He50 N (49.985% Ar, 50% He, 0.015% N) both face and root 10 l∙min-1 5
2.0992 filler
1.4316 filler
Parameters for the welding tests Sheet grade 1.4371 1.4371 1.4371 1.4371 1.4376 1.4376 1.4376 1.4371 1.4371 1.4371 1.4371 1.4376 1.4376 1.4376
Sheet grade 1.4371 1.4376 1.4318 1.4301 1.4376 1.4318 1.4301 1.4371 1.4376 1.4318 1.4301 1.4376 1.4318 1.4301
I (A) 78 82 75 74 73 76 77 80 80 80 80 85 75 85
U (V) 19.3 19.3 19.5 19.4 19.3 19.4 19.3 15.4 15.1 16.5 15.8 15.1 15.0 14.5
v (cm∙min-1) 26.7 23.5 23.7 23.8 22.3 23.4 24.3 35.5 31.2 41.0 35.6 43.3 33.2 41.3
Q (kJ∙mm-1) 0.27 0.32 0.30 0.29 0.30 0.30 0.29 0.17 0.19 0.15 0.17 0.14 0.16 0.14 6
Quantitative metallography • Standard metallographical preparation • Mechanically grounded, polished • Etched: methanolic aqua regia, 20-30 s (45 ml HCl+15 ml HNO3+ 20 ml methanol)
• Grain size according to ASTM E 112 standard
• Zones of the joints • WM: Weld Metal, fusion zone • HAZ1: Heat Affected Zone, next to WM • HAZ2: Heat Affected Zone, finer grain structure
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Quantitative metallography
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Quantitative metallography
1.4371
1.4376
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Normalized grain size in the HAZ
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Normalized grain size in the HAZ
HAZ1
1.4371>1.4318 >1.4376>1.4301
HAZ2 1.4318>1.4371> 1.4376> 1.4301 (refined)
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Micro hardness testing Standard method, ASTM E384 On etched specimen, 500 g load (HV0.5), 0.3 mm step
1.4371
2.0992
1.4301
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Mean hardness values in the WM
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Mean hardness values in the HAZ
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Mean hardness values in the HAZ
1.4371
290 – 200 HV0.5
1.4376
280 – 195 HV0.5
1.4318
188 – 215 HV0.5
1.4301
176 – 194 HV0.5
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Determination of the tensile properties • Standard method, EN ISO 6892-1 • MTS 810 machine, 3 mm∙min-1 crosshead speed • 3 samples in every combination • Tensile strength (Rm), Necking (Z) • Elongation: of the joint and the sides (A11.3 , A 5.65)
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Mean tensile strength of the joints
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Fracture elongation of the joints
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Summary • Base mat.: 1.4371, 1.4376 + 1.4318, 1.4301 with filler 1.4430, 1.4316, 2.0992 succesfully jointed via GMAW and MIG-brazing • Grain coarsening: • 1.4371>1.4318 >1.4376>1.4301 – HAZ1 • 1.4318>1.4371> 1.4376> 1.4301 (refined) – HAZ2 • Rm: 600-670 MPa – GMAW 400-500 MPa – MIG-brazing • A11.3: 10-28% – GMAW / 2-16% – MIG-brazing • Mn: increase HV0.5
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Acknowledgements • Arcelormittal FCE Hungary Kft. • Outokumpu Distribution Hungary Kft. • Dunakeszi Járműjavító Kft. • GRANIT Grinding Wheel Ltd. • This paper was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences grant number: BO/00196/16/6 and by The Hungarian Research Fund, NKTH-OTKA PD 120865 (K. Májlinger).
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MIG-welding and MIG-brazing of different austenitic stainless steel sheets
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