JOINT HYDROGEN SUSCEPTIBILITY OF 304 SS WELDED WITH TITANIUM

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JOINT HYDROGEN SUSCEPTIBILITY OF 304 SS
WELDED WITH TITANIUM

EPNM2014-Kraków

• Eva MAZANCOVÁ1, Dimitrij Ostroushko1,
• Karel Saksl2, Adam Nieslony3
• 1VŠB-TU of Ostrava
• Faculty of Metallurgy and Materials Engineering
• Czech Republic
• 2Institute of Material Research of SAS, Košice,
  Slovak Republic
• 3Opole University of Technology, Faculty of
  mechanical Engineering, Opole, Poland

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EPNM2014-Kraków
AIM To show H2 response of 304 SS and Ti weld in
conditions of fatigue test (tensile-pressure) and
of the HIC exposition
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EXPERIMENTAL MATERIAL

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• Sheets (1106Ti) x 2600 x 2600 mm
• welded by Explomet-Opole
• 304 SS (wt. )
• 0.03C-0.45Si-1.96Mn-18.4Cr-9.7Ni-
• 0.006P-0.011S
• Ti (wt. )
• 0.01C-0.05Fe-0,05O-0,005N-0.006H

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EPNM2014-Kraków
EXPERIMENTAL PROCEDURE
Weld Ti 
Fatigue bar 90x?10 mm  
as-received state

(0.1M H2SO4 solut./8 hcurrent density of
15 mA.cm-2) Cyclic fatigue stress
(tensile-pressure) at amplitude of 20 Hz (40 Hz
HT without H2) - CSN 42 0363
600C/1.5h (HT)
after H-charging
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EPNM2014-Kraków
EXPERIMENTAL PROCEDURE
HIC NACE St. TM0284-2011   Samples 20 x
14.5 x 100 mm Crack length ratio CLR Crack
thickness ratio CTR Crack sensitivity ratio CSR
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HIC SAMLES EVALUATION
CLR
100.?a/w () CTR 100.?b/T ()
CSR 100.?(a.b)/w.T () Interface analysis
using EDAX and Synchrotron

EPNM2014-Kraków
Ti  304 SS a crack length in w
b crack thickness in T
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MICROSTRUCTURE BIMETAL INTERFACE

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b
a
304 SS
Ti 
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MICROGRAPH - ADIABATIC BANDS

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Ti 
9
MICROGRAPHS 3 mm AWAYBONDING LINE

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b
a
304 SS
Ti
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HIC EVALUATION individual values ()

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• S CLR (15) CTR (5) CSR (2)
• 0HT/HT 0HT/HT 0HT/HT
• 1.04/2.19 2.47/0.14 0.003/0.001
• 1.25/1.37 2.25/0.13 0.01/0.002
• 2.04/3.08 1.99/0.62 0.01/0.003
• 4 3.07/3.68 2.17/0.70 0.01/0.002
• 3.42/0.50 2.93/0.04 0.01/0.001
• 6 4.15/2.37 3.75/0.16 0.01/0.002
• 2.25/1.80 2.30/3.66 0.01/0.012
• 1.92/1.60 1.90/2.80 0.01/0.005
• 3.02/1.60 2.51/2.62 0.01/0.013

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HIC EVALUATIONmean values ()

EPNM2014-Kraków

• S CLR CTR CSR
• 1.44/2.21 2.47/0.30 0.01/0.002
• 2
• 4 3.55/1.52 2.95/0.30 0.01/0.002
• 5
• 6
• 2.39/1.67 2.24/3.00 0.01/0.01
• 8
• 9

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HIC EVALUATION

EPNM2014-Kraków
a
b

total cracks 84 (without the HT)
56 (after the HT) length 0.01-0.08 mm
thickness 0.01-0.22 mm
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INTERPHASE ANALYSES

EPNM2014-Kraków
1-304 SS 2-68-98Ti
3-16Ti-16Cr-57Fe-8Ni Al,Si,Mn bal. 5-65-90Ti
a
5
b
4-20Ti-11Cr-61Fe-6Ni Al, Si, Mn bal.
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FATIGUE TESTS

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FRACTURE SURFACE ANALYSIS

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FRACTURE SURFACE ANALYSIS

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a
WHT (without the HT) H-charging
b
AHT (after the HT) H-Charging
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FRACTURE SURFACE ANALYSES (at.)


EPNM2014-Kraków

Mark Si Ti Cr Mn Fe Ni
1a 0.6 19.2 16.7 1.5 54.9 7.1
1b 0.9 19.7 16.7 1.6 54.1 7.0
1c 0.9 21.1 16.2 1.5 53.0 7.3
2a   97.1 0.5   2.0 0.4
2b 0.2 65.5 4.9 0.6 24.3 4.5
3a 0.6 45.3 11.3 1.1 36.9 4.8
3b 0.6 42.2 11.2 1.1 40.3 4.6
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INTERPHASE ANALYSISUSING SYNCHROTRON

EPNM2014-Kraków
Raster step size 1?m, total length 401
?m X-ray focused to 2.2x34 ?m, beamline P07 at
Petra III (electron storage ring operating at
energy of 6 GeV with beam current 100 mA (18)
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CONCLUSIONS

EPNM2014-Kraków
Safe load boundary of the HTH-charged bars (at
20Hz) showed 17 of tensile strength of bimetal
weld in clad state and/or 12 (at 40 Hz) in case
of H-charged samples without the HT. Higher
amplitude (40 Hz) resulted in threshold level
decrease of the HT samples without H-charging
approx. by 25 MPa. Fracture surfaces
predominanty indicated the rupture in areas where
6697 at. of Ti was revealed representing
bonding line. On surface, lower portion of Ti a
presence of the FeTi and/or Fe2Ti with Cr
partially substituting the Fe could indicate.

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CONCLUSIONS

EPNM2014-Kraków
After the HIC exposition cracks were observed in
areas of curls only, where inter-metallic phases
of the Fe2Ti were detected using monochromatic
synchrotron radiation, while the EDAX analysis
showed the most frequent mixed phases approx. (in
at. ) with 20 Ti, 11 Cr, 60 Fe showed. All HIC
parameters were satisfactory and complied with
the requirements of NACE Standard and ANSI/API
specification 5L. After the HT, results were more
satisfactory in average.

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CONCLUSIONS

EPNM2014-Kraków
After the HIC exposition, more cracks were
detected in samples without the HT unlike the HT
ones. Cracks showed 45-90 orientation towards
the bonding line and none ran to any basic
material. Cracks were maximally 0.08 mm long and
0.22 mm thick (2 cases). By application of
monochromatic synchrotron radiation Fe2Ti phase
in wave curls was revealed. Presence of Fe-fcc,
Fe-bcc and Ti-hcp will be discussed in next
paper.

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ACKNOWLEDGMENT

EPNM2014-Kraków

•  
• This paper was created within the project
  7AMB14SK023Mobilities, 02613/2013/RRC
  International Research Teams sponsored by
  Northern Moravian region, within the project SP
  2014/62 Specific Research in Metallurgical,
  Material and Process Engineering and No. L01203
  L Regional Materials Science and Technology
  Centre Feasibility Program founded by Ministry
  of Education, Young and Sports of Czech Republic.
  Special thanks belongs to EXPLOMET for an
  important cooperation.

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THANKS FOR YOUR ATTENTION

EPNM2014-Kraków
Slovak Academy of Sciences Institute of Material
Research Kosice, Slovakia