Hydrogen Effects in Materials 1

8/10/2019 Hydrogen Effects in Materials 1

1/49

Hydrogen Effects in Materials

Brian Somerday

Sandia National LaboratoriesLivermore, CA, USA

3rd European Summer School on Hydrogen Safety

University of Ulster, Belfast, UK

July 28, 2008


2/49

Outline

IntroductionH

2interactions with metal components

Safety concern: hydrogen embrittlement (HE)

Methods to assess material performance

Variables affecting HE Material

Environmental

Mechanical


3/49

Outline

Considerations for materials selection

Component design

Design approach

Material property measurement

Example design analysis

Recommendations


4/49

H2 containment components

On-board fuel tanks Manifold components


5/49

H2 containment components

PipelinesTransport and

stationary tanks


6/49

H2 interactions with metal components

H2 gas

1) H2 gas

2) H2 adsorption

3) H2 dissociation to H

4) H absorption

5) H diffusion


7/49

Two principal safety concerns

H2 permeation through wall of structure

Effectively results in H2 leak

Hydrogen embrittlement (HE) of structural

metal Crack propagation through wall of structure

HE mechanisms involve H in solution

Temperatures < 200 oC

Other H-related degradation mechanismsoperate >200 oC


8/49

H2

H2

H2

H2

H2

H2 H2

stress

stress

defect

component

surface

H2H

2

H2

H2

H2

HH

HH

H2 H2 H2H

2

H absorbsinto surface

H2

H2

H2

H

H

H H

H2 H

2 H2H2

H concentrates

at defect

H

H

HH

H

H2

H2

H2

H2H

2

H2 H2 H

2H2HH H

H H HH

H

H causes embrittlement

and crack propagation

HE enables crack propagation


9/49

Hydrogen embrittlement mechanisms

Hydrides

Hydrogen-EnhancedLocalized Plasticity

(H.E.L.P.)

Hydrogen-EnhancedDecohesion

H

H

H

H

HH

H

1 2

HHHHH

HHH

HH

HH

H

H

H

1 > 2

HHH

H

HH

HH

HH

H HH

void

particle

hydrides

C. Beachem, H. Birnbaum,

I. Robertson, P. Sofronis

A. Troiano, R. Oriani

D. Westlake,

H. Birnbaum


10/49

HE due to hydrogen-enhanced decohesion

Intergranular HE can be devastating

Barthlmy, 1st ESSHS, 2006


11/49

Material performance: test methods

strength of materials:

u,y,f, RA

S-N

fracture mechanics:KIH, KTH

da/dN vs

K

dl/d t > 0

H2

H2H2

H2H2

H2

H

HH

H

HH

HH

dl/d t > 0

l

HH

HH H

HH

H

H

H

d/dt 0

H

H

H

HH H

H

H

H

H

HH H

H

HHHH2 H2H2H2H2

H2

H2H2

d/dt 0


12/49


HE manifested by reduced fracture

toughness

H2gas pressure (kpsi)

0 5 10 15 20 25

Stressintensityfactor,K

(ksi-in1/2)

0

50

100

150

200

250

300

H2gas pressure (MPa)

0 25 50 75 100 125 150

Stressintensityfactor,K

(MPa

-m1/2)

0

50

100

150

200

250

300KJIc

KTH

X100 ferritic steelWOL specimens

C-L orientation

25oC

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2


13/49


HE manifested by increased fatigue

crack growth rate

Stress intensity factor range, K (ksiin1/2)1 10 100

Fatiguecrackgrowthrate,da/dN

(in/cycle)

10-8

10-7

10-6

10-5

10-4

10-3

10-2

X42 ferritic steelfrequency = 1 Hz

1000 psi H2, R=0.1

1000 psi N2, R=0.1

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2

Cialone and Holbrook,Met Trans A, 1985


14/49

Fuel tanks

Aluminum or polymer

lined composite H2 pressure < 70 MPa

Manifold components

Austenitic stainless

steel H2 pressure < 138 MPa

Low material strength

No welds

Material performance: service experience


15/49

Material performance: service experience

Storage tanks

Low-alloy ferriticsteel

H2 pressure < 42 MPa

Limited materialstrength

No welds

Pipelines

C-Mn ferritic steel

H2 pressure < 14 MPa

Low material strength

No pressure cycling


16/49

H2 compatibility guidelines for metals

Materials favored for H2 service

austenitic stainless steels, aluminum alloys,

low-alloy ferritic steels, C-Mn ferritic steels,

copper alloys

Materials commonly avoided in H2 service high-alloy ferritic steels, nickel alloys,

titanium alloys

HE susceptibility can be sensitive

to many variables


17/49

Variables affecting HE

All metals can be susceptible to HEdepending on

Material variables Environmental variables

Mechanical variables

Trends demonstrated from laboratory

test methods Emphasize fracture mechanics data Emphasize ferritic steels, austeniticstainless steels, aluminum


18/49

Material variable: strength (hardness)

Yield strength (MPa)600 700 800 900 1000 1100

KTH

(MPa-m

1/2)

0

20

40

60

80

100

120

Yield strength (ksi)90 105 120 135 150

K

TH

(ksi-in1/2)

0

20

40

60

80

100Pressure Vessel SteelsH

2gas pressure = 41 MPa

4130 steel

4145 steel

4147 steel

Loginow and Phelps,

Corrosion, 1975

Strength promotes HE in all materials

Technologically important trend

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2


19/49

Material variable: alloy composition

Alloy composition affects intergranular

HE in ferritic steels

[Mn + 0.5Si + S + P] (wt%)0.0 0.2 0.4 0.6 0.8 1.0

KTH

(MPa-m

)

0

20

40

60

80

100Ni-Cr-Mo ferritic steel

YS= 1450 MPa

110 kPa H2gas

296 K

B7Mn=0.007Si=0.002P=0.003S=0.003Mn=0.02

Si=0.01P=0.014

S=0.003

Mn=0.09Si=0.01P=0.012S=0.005

Mn=0.02Si=0.27P=0.0036S=0.005

Mn=0.23Si=0.01P=0.009S=0.005

B2Mn=0.68Si=0.08

P=0.009S=0.016

Mn=0.72Si=0.01P=0.008S=0.005

B6Mn=0.72Si=0.32P=0.003S=0.005

Mn=0.75Si=0.20P=0.006S=0.004

Bandyopadhyay et al.,Met Trans A, 1983

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2


20/49

Material variable: alloy composition

Nickel affects deformation and/or

martensite formation in stainless steels

San Marchi et al.,IJHE, 2008

H-precharged

non-charged 316 stainless steels

HH

HH

H

H

dl/dt > 0


21/49

Material variable: welding

Weld microstructure can promote HE

Hardness, residual stress also affect HE

Stainless steel weld Weld tested after H2 exposure

base metal weld


22/49

Environmental variable: H2 pressure

HE more severe at higher H2 pressure

for all materials

H2gas pressure (MPa)0 30 60 90 120 150

KTH

(MPa-m

1/2)

0

30

60

90

120

150

180

H2

gas pressure (ksi)0 5 10 15 20

KTH

(ksi-in1/2)

0

20

40

60

80

100

120

140

160Pressure Vessel Steels

4130 steel (YS=634 MPa)4145 steel (YS=669 MPa)4147 steel (YS=724 MPa)

Loginow and Phelps,

Corrosion, 1975

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2


23/49

HE can be maximum at ambient temperature

HH

HH

HH

dl/dt > 0

Caskey, Hydrogen

Compatibility Handbookfor Stainless Steels,

1983

Environmental variable: temperature


24/49

Gas impurities can inhibit or intensify

HE in ferritic steels

Environmental variable: H2 purity

(da/dN

)H2

+additive

/(da/d

N)H

2

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

O2

0.10%

2.25 Cr-1 Mo ferritic steel

YS= 430 MPa

1.1 MPa H2gas

K = 24 MPamfrequency = 5 HzR = 0.1293 K

CO

0.99%

SO2

1.10%

H2O

0.03%

CH4

0.98%

CO2

1.01%

CH3SH

1.04%

H2S

0.10%

Fukuyama et al.,

Pressure VesselTechnology, 1992

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2


25/49

Water vapor promotes HE in

aluminum alloys

Environmental variable: H2 purity

Speidel, Hydrogen Embrittlementand Stress Corrosion Cracking, 1984

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2


26/49

Mechanical variable: loading rate

HE more severe at lower loading rates

in all materials

Loading rate, dK/dt (MPa-m1/2

/min)0.1 1 10 100

K

IH

(MPa-m

1/2)

0

20

40

60

80

1004340 ferritic steel

YS= 1235 MPa

550 kPa H2gas

297 K

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt 0

H2H2H2

H2

H2

H2

H2

H2

Clark and Landes,

ASTM STP 610, 1976


27/49

HE more severe at lower load cycle

frequency in all materials

Mechanical variable: load cycle frequency

K (MPa-m1/2)0 15 30 45 60

da

/dN

(m/cycle)

0.1

1

10

100SA 105 ferritic steel103 MPa H

2gas

load ratio = 0.1

1.0 Hz35 MPa He gas

1.0 Hz

0.1 Hz

0.01 Hz

0.001 Hz

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2

Walter and Chandler, Effectof Hydrogen on Behavior of

Materials, 1976


28/49


1) HE data or service experience shouldnot be extrapolated


0 30 60 90 120 150

KTH

(MPa-m

1/2

)

0

30

60

90

120

150

180

H2

gas pressure (ksi)0 5 10 15 20

KTH

(ksi-in1/2)

0

20

40

60

80

100

120

140


4130 steel (YS=634 MPa)4145 steel (YS=669 MPa)4147 steel (

YS=724 MPa)

Yield strength (MPa)600 700 800 900 1000 1100

KTH

(MPa-m

1/2)

0

20

40

60

80

100

120

Yield strength (ksi)90 105 120 135 150

KTH

(ksi-in1/2)

0

20

40

60

80

100Pressure Vessel SteelsH

2gas pressure = 41 MPa

4130 steel

4145 steel

4147 steel

H2 compatibility must be established for

specific conditions


29/49


2) HE can be severe in alloys consideredcompatible with H2

HH

HH

HH

dl/dt > 0

316 stainless steels

Intersections of variables important


30/49


3) Materials selection may balance H2compatibility with other constraints

highcryogenic to

low

intermediate

to highintermediatealuminum

low to

intermediate

ambient to

high

low to highlowC-Mn/low-

alloy steels

highcryogenic to

highlow to highhighaustenitic SS

HE resistanceTemperature

range

Specific

strengthCostMaterial


31/49


4) Materials must be qualified for H2 service

based on Material property measurements under

relevant conditions

Material variables Environmental variables

Mechanical variables

Design approach for component


32/49

Design based on fracture mechanics

Local stress drives crack extension

localH2H

2

H2

H2

H2

H2 H

2

stress ()

defect

component

surface

H2H

2

H2

H2

H2

H2H

2

H2 H2 H

2H2

local = c

stress ()


33/49

)(2

ijij fr

K=

Local stress described by stress-

intensity factor, KCrack extension governed by criticalK values

Design based on fracture mechanics


34/49

Component design: sustained-load cracking

H2 induces time-dependent crack

propagation under static loading

p

a

p

aH2

H2H2

N2N2 N

2

time

a

p

crack in H2

crack in N2


35/49

Sustained-load cracking proceeds

when K > KTH

p

aH2H2

K = p * f(a/t,Ri,Ro)

Ri

Ro

t

time

a

K

KTH

measured in

laboratory

Component design: sustained-load cracking


36/49

Crack growth under cyclic loading

accelerated by H2

p

a

pa

H2H2H2

N2N2 N

2

a

Number of pressure cycles, N (time = N/f)

p

crack in H2

crack in N2

p

Component design: fatigue crack growth


37/49

Fatigue crack growth rates (da/dN)

are a function of K

paH2H2


Ri

Ro

t

da/dN

K

measured in laboratory

H2 gas

measured in laboratory

N2 gas

da/dN = C[K]m

Component design: fatigue crack growth


38/49

Component design analysis

Objective: calculate number of pressure cycles, Nc,to grow crack to critical length, ac

Calculation requires material property

measurements: KTH and da/dN vs

K

a t

ac

Number of pressure cycles, NN

c

critical crack depth for

sustained-load crackingcycles to

critical crack depth


paH2H2

Ri

Ro

t

a


39/49

Measurement: fatigue crack growth

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2

HH

H

d/dt > 0

H2H2H2

H2

H2

H2

H2

H2


40/49

Measurement gives crack length vs

number of cycles in design analysis

a = C[p * f(a/t,Ro,Ri)]m

Number of pressure cycles, N

a

K (MPa-m1/2)0 15 30 45 60

da/dN

(m/cycle)

0.1

1

10

100SA 105 ferritic steel103 MPa H

2gas

load ratio = 0.1

1.0 Hz35 MPa He gas

1.0 Hz

0.1 Hz

0.01 Hz

0.001 Hz

Measurement: fatigue crack growth

da/dN = C[K]m


41/49

Measurement: cracking threshold

Load(

P)

Time in H2

Po Ko

Loading bolt

Load cell

13 mm

PTH KTH

Wedge Opening Load

(WOL) specimen


42/49

Measurement gives critical crack depth(ac) in design analysis

ac/t = g(KTH,p,Ro,Ri)

ac

Number of pressure cycles, NNc

a


0 30 60 90 120 150

KTH

(MPa-m

1/2)

0

30

60

90

120

150

180

H2gas pressure (ksi)

0 5 10 15 20

KTH

(ksi-in1/2)

0

20

40

60

80

100

120

140


4130 steel (YS

=634 MPa)

4145 steel (YS=669 MPa)4147 steel (YS=724 MPa)

Measurement: cracking threshold

E l d i l i f H i li


43/49

Example design analysis for H2 pipeline

Parameters for H2 pipeline(ASME, Hydrogen Standardization Interim Report, 2005)

X42 ferritic steel Inner radius, Ri = 15 cm

Wall thickness, t, from 0.5 to 1.3 cm

Maximum pressure, p = 10 MPa

Existing defect with depth aoand length parallel to pipe axis

p

RiRo

aot



44/49

Case 1: t=0.8 cm (h=65% SMYS) and ao/t=0.10



p

10 MPa

N

1 MPa

cycle 1

K1=f(ao,p,Ro,Ri,t)a=(2.51x10-12)K16.56

a1=ao+a

cycle 2

K2=f(a1,p,Ro,Ri,t)a=(2.51x10-12)K26.56

a2=a1+a

ao a1 a2


p

RiRo

aot

h



45/49

Material/component performance canbe quantified with design analysis

number of pressure cycles0 50000 100000 150000 200000 250000

crack

depth/wallt

hickness,a/t

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

hydrogent=1.3 cm

h=43% SMYS

nitrogent=1.3 cm

h=43% SMYS

X42 Pipelinepressure cycle = 1 - 10 MPainner diameter = 30 cm

X

X

critical crack depthcalculated from K

Ic

critical crack depthcalculated from K

TH


Fatiguecrackgrowthrate,

da/d

N

(in/cycle)

10-8

10-7

10-6

10-5

10

-4

10-3

10-2


da/dN=(3.55x10-11

)K3.83

da/dN=(2.51x10-12

)K6.56

1000 psi H2, R=0.1

1000 psi N2, R=0.1




46/49

Performance depends on both materialproperties and component design

number of pressure cycles0 5000 10000 15000 20000 25000 30000 35000 40000 45000

crack

depth/wallt

hic

kness,a/t

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

case 1t=0.8 cm

h=65% SMYS

case 2t=1.3 cm

h=43% SMYS

case 3t=1.3 cm

h=43% SMYS

X42 PipelineH

2gas

pressure cycle = 1 - 10 MPainner diameter = 30 cm

X

X X

critical crack depthscalculated from K

TH


Fatiguecrackgrowthrate,

da/d

N

(in/cycle)

10-8

10-7

10-6

10-5

10-4

10-3

10-2


da/dN=(2.51x10-12

)K6.56

1000 psi H2, R=0.1

case 1 initial K

case 2 initial K

case 3 initial K


Recommendations


47/49

1) Austenitic stainless steels, aluminum

alloys best candidates for H2 service

Based on service experience and testing

Do not extrapolate performance or test data

Define temperature, alloy composition for

austenitic stainless steels

Define water vapor content of gas for

aluminum alloys

Design analysis can quantify safety margins

Recommendations

Recommendations


48/49

2) Ferritic steels are susceptible to HE

under wide range of conditions Service experience may be adequate but

design analysis required in many cases

Measure properties under specific conditions Material: strength, alloy composition,

fabrication (e.g., welding)

Environment: H2 pressure, H2 composition,temperature

Recommendations

Recommendations


49/49

3) Nickel alloys, titanium alloys are generally

not recommended for H2 service Design analysis required

May require other measures such as H2

permeation barrier

Recommendations

Documents

Hydrogen Effects in Materials 1