•
Performance of the analytical
techniques employed in
characterization and certification of
stainless steel materials
by
Ingemar Gustavsson
Analytical Chemistry Group
Corrosion and Metals Research Institute
Drottning Kristinas väg 48
SE 114 28 Stockholm, Sweden
E-mail: ingemar.gustavsson@simr.se
Definitions of RMs and CRMs
according to ISO-Guides 30-35
____________________________
• Reference Material (RM)
• A material, sufficiently homogeneous and
stable with respect to one or more properties,
which have been established to be fit for its
intended use in a measurement process
• Certified Reference Material (CRM)
• An RM characterized by a metrologically valid
procedure, accompanied by a certificate that
states the value of the specified property, its
associated uncertainty, and a statement of
metrological traceability
Production of certified reference materials (CRM)
YES
Producers´
Group-ECRM
Repalcement of an
exhausted ECRM
Demand of a
new CRM is
investigated
No !
YES
NCRMWG The
JK-series
Replacement of an
exhausted CRM
YES
Supplier is requested
(Nordic countries)
Supplier is requested
(Nordic, British,
French, German)
Bars for homogenity
test
Bars for homogenity
test
Delivery to SIMR or
BAM, BAS, CTIF,
IRSID
Delivery to SIMR
Possibly new
homogeneity test
Possibly new
homogeneity test
Production of certified reference materials (CRM)
Possibly new
homogeneity test
Possibly new
homogeneity test
Preparation chips
(drillings)
Preparation chips
(drillings)
Preanalysis according
to ISO-standards
Preanalysis according
to ISO-standards
Distribution of chips to
laboratories for
certification analysis
(20-30)
Distribution of chips to
laboratories for
certification analysis
(15-20)
4 UK
4 French 4 German
Other
European
European
Nordic International
Characteristic steel elements
Concentrations given in % (m/m)
• C, Si, Mn, P, S, Cr, Mo, Ni, N, (Fe)
•
•
•
•
•
C
Mn
S
Mo
N
•
Low alloy steel C, Si, Mn, P, S, N
•
•
High alloy steel C, Si, Mn, P, S, Cr, Mo, Ni, N
(Stainless steel)
•
•
•
Tool steel
C, Si, Mn, P, S, Cr, Mo, Ni, N, W, V, Co
”Special steel” C, Si, Mn, P, S, Cr, Mo, Ni, N plus
e.g. Al, Si, Nb, Ti, Cu, Ce
0,01 - 2
0,3 - 12
0,0005 - 0,2
0,005 - 5
0,001 - 0,3
Si
P
Cr
Ni
Fe
0,05 - 3
0,001 - 0,02
0,1 - 30
0,01 - 30
35 - 99
Chemical analysis of
stainless steel
• C and S Combustion - infrared detection
• (C - 0,003-4,5 %; S - 0,0005 - 0,2 %)
– Oxidation by oxygen gas at 2100 oC;
formation of CO2 and SO2
– Calibration against BaCO3; Na2CO3 or
sucrose
– Calibration against K2SO4
– (Calibration against CRMs)
Chemical analysis of
stainless steel
• Si - Spectrophotometry (0,01-0,2%)
–
–
–
–
–
–
Dissolution by H2SO4/HNO3
Filtartion
Ignition of acid-insoluble Si with Na2O2
Add MnO4- - solution - pink solution
Add MoO4 2- - solution
Add ascorbic acid solution - formation of
molybdosilicate complex (blue)
– Measurement at 810 nm
– Calibration against ”SiO2 -solution”
• Si - Gravimetry (0,1 - 5 %)
– Oxidation by HClO4-fuming-formation of
SiO2
– Filtration
– Addition of HF - formation of SiF4
– Ignition
– Weighing
Chemical analysis of
stainless steel
• Mn - AAS - flame (0,002 - 2 %)
–
–
–
–
–
Dissolution by HCl/HNO3 (HF)
Add HClO4 - fuming
Filtration
Measurement at 279,5 nm
Calibration against matrix-matched Mn solution
Chemical analysis of
stainless steel
• P - Spectrophotometry (0,001 - 1,0 %)
– Dissolution by HCl/HNO3 (HF)
– Add HClO4 - fuming
– Cr content > 0,1 % is removed by addition of
HCl - formation of volatile CrO2Cl2
– Add NaNO2 - reduction of dichromate
– Add H3BO4 - formation of tertafluoroboric acid
– Add metavanadate and heptamolybdate solutionsformation of phosphovanadomolybdate complex
– Extraction with 4-methyl-2-pentanone
– Measurement of organic solvent at 355 nm
– Calibration against KH2PO4
(orthophosphate) - solution
Chemical analysis of
stainless steel
• Cr and V - Potentiometric titration
Cr (1 - 30 %); V (0,5 - 10 %)
– Dissolution by HCl/HNO3/HF in aTeflon
pressure vessel in micro-wave assisted system
– Add H3PO4/H2SO4 - oxidation to Cr(VI) and
to V(V), respectively
– Titration with Fe(II) giving Cr(III) and
V(IV)
– Oxidation with MnO4- -solution giving V(V)
and not Cr(VI)
– Excess of MnO4- is reduced by NO2– Excess of NO2- is eliminated by urea
– Standardisation using pure K2Cr2O7
Chemical analysis of
stainless steel
• N - Melt extraction - Thermal Conductivity
(0,002 - 0,6 %)
– Melt extraction at 2700 oC in graphite
crucible and purging helium
– Calibration against KNO3
– (Calibration against CRMs)
Chemical analysis of
stainless steel
• O - Melt extraction - Infrared detection
(0,0001 - 0,02 %)
– Melt extraction at 2200 oC in graphite
crucible and purging helium
– Calibration against KNO3
– Calibration against Dy2O3 alt TeO2
– (Calibration against CRMs)
Chemical analysis of
stainless steel
• Trace elements (< 0,01 %)
•
Li, Be, B...Ti…Nb, Mo…Sn, Sb… Ce, La…W…Pb, Bi, Th, U
– Dissolution in HCl/HNO3/(HF) in a Teflon
pressure vessel using a micro-wave assisted
system
– Dilution to suitable analytical volume
– Addition of internal standard (usually 1- 3)
of Y, Rh, In, Re, Ir, Tl
– Calibration against matrix-matched
elemental solutions
ECISS
EUROPEAN COMMITTEE FOR IRON AND STEEL STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION DU FER ET DE L’ACIER
EUROPÄISCHES KOMITEE FÜR EISEN-UND STAHLNORMUNG
EUROPEAN CERTIFIED REFERENCE MATERIAL (EURONORM – CRM)
CERTIFICATE OF CHEMICAL ANALYSIS
EURONORM – CRM No.
274-1 VANADIUM STEEL
LABORATORY MEANS (4 Values) mass content in %
Line No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
MM
sM
sW
Line No
1
2
3
4
C
1.5450
1.5499
1.5500
1.5547
1.5580
1.5586
1.5600
1.5620
1.5645
1.5660
1.5667
1.5717
1.5740
1.5758
1.5760
1.5761
Si
1.0273
1.0390
1.0467
1.0496
1.0526
1.0537
1.0558
1.0591
1.0632
1.0649
1.0685
1.0692
1.0724
1.0771
-
Mn
0.3848
0.3881
0.3887
0.3900
0.3905
0.3907
0.3920
0.3958
0.3972
0.3982
0.3991
0.4017
0.4024
0.4030
0.4070
0.4078
0.4097
P
0.0134
0.0140
0.0144
0.0144
0.0145
0.0145
0.0146
0.0146
0.0147
0.0147
0.0150
0.0152
0.0154
0.0159
0.0165
-
S
0.0086
0.0087
0.0087
0.0088
0.0093
0.0094
0.0095
0.0095
0.0098
0.0098
0.0098
0.0099
0.0099
0.0104
0.0109
0.0110
Cr
7.9580
7.9950
8.0012
8.0105
8.0134
8.0152
8.0153
8.0381
8.0461
8.0491
8.0591
8.0734
8.0840
8.0900
8.0922
-
Mo
1.3930
1.4177
1.4293
1.4320
1.4480
1.4487
1.4553
1.4586
1.4595
1.4650
1.4679
1.4737
1.4858
1.4916
1.5002
Ni
0.0670
0.0735
0.0740
0.0742
0.0750
0.0764
0.0775
0.0777
0.0779
0.0781
0.0783
0.0788
0.0795
0.0804
0.0805
0.0868
Cu
0.0267
0.0267
0.0267
0.0271
0.0278
0.0279
0.0281
0.0282
0.0282
0.0284
0.0285
0.0285
0.0288
0.0288
0.0290
0.0296
N
0.0724
0.0744
0.0753
0.0760
0.0762
0.0764
0.0770
0.0770
0.0772
0.0772
0.0772
0.0777
0.0780
0.0794
0.0795
0.0800
1.5630
0.0100
0.0060
1.0568
0.0139
0.0059
0.3970
0.0075
0.0035
0.0148
0.0008
0.0004
0.0096
0.0007
0.0003
8.0404
0.0404
0.0224
1.4551
0.0287
0.0085
0.0770
0.0042
0.0013
0.0282
0.0008
0.0004
0.0770
0.0019
0.0008
As
0.0013
0.0013
0.0014
Co
0.0212
0.0213
0.0226
0.0266
Pb
0.000060
0.000065
0.000068
Sn
0.00081
0.00093
0.00095
0.00150
Ti
0.0006
0.0012
0.0014
Sb
0.000185
0.000190
0.000200
V
3.9578
3.9625
3.9666
3.9703
3.9879
3.9968
3.9973
3.9975
4.0024
4.0042
4.0060
4.0146
4.0197
4.0413
4.0461
4.0623
4.0662
4.0800
4.0100
0.0366
0.0185
W
0.0072
0.0073
0.0075
0.0078
0.0081
0.0084
0.0084
0.0086
0.0086
0.0088
0.0090
0.0093
0.0100
0.0107
0.0112
-
O(*)
0.0017
0.0021
0.0021
0.0021
0.0022
0.0023
0.0026
0.0026
0.0026
0.0028
0.0029
0.0030
0.0030
0.0030
0.0032
0.0032
0.0087
0.0012
0.0003
0.0026
0.0004
0.0002
Altot
0.0005
0.0015
0.0018
0.0024
0.0025
0.0026
0.0026
0.0029
0.0030
0.0037
0.0039
-
Additional value for information: B ~ 5 g/g
Values given in italic type are for information only
sb  sw / 4
2
MM: Mean of the laboratory means, sM: Standard deviation of the laboratory means
2
sM =
sw: Intralaboratory standard deviation, sb: Interlaboratory standard deviation
The laboratory mean values have been examined statistically to eliminate outlying values.
Where a ”-"appears in the table it indicates that an outlying value has been omitted by either the Cochran or Grubbs Test.
( )
* Values refer to solid samples ; thus oxygen determination shall only be done on disc samples excluding a centre diameter of 6 mm .
C
Si
Mn
MM
C(95%)
1.563
0.005
1.057
0.008
0.397
0.004
N
V
MM
C(95%)
0.0770
0.0010
4.010
0.018
CERTIFIED VALUES mass content in %
P
S
Cr
W
0.0087
0.0007 n
0.0148
0.0004
0.0096
0.0004
8.041
0.023
Mo
Ni
Cu
1.455
0.016
0.077
0.002
0.0282
0.0004
O
0.0026
0.0002
The half-width confidence interval C(95%)= t x sM /
where t is the appropriate Student’s t value and n is the number of acceptable mean values.
For further information regarding the confidence interval for the certified value see ISO Guide 35:1989 section 4.
This reference material was prepared in accordance with the recommendations
set out in ISO Guides 30 – 35 and issued by:
Swedish Institute for Metals Research (SIMR)
Drottning Kristinas väg 48, SE-114 28, Stockholm, Sweden
On behalf of: The Iron and Steel Nomenclature Co-ordinating Committee (COCOR) of the ECISS,
after approval by all the participating laboratories and all the producing organisations.
(France-IRSID/CTIF; Germany-Iron and Steel CRM Working Group: VDEh,
BAM & MPI für Eisenforschung; UK-BAS Ltd; Nordic Countries-Nordic CRM Working Group)
Certified
Institute
ISO 17025
Accredited
Round-Robin test. Concentrations of 30 elements in a high
alloy steel - JK 37.
n = number of participating laboratories; concentrations in g/g
Major element
n
Cert.value
17120  35
3
17300
Micro elements
Si
1350  100
P
157  6
V
740  35
Co
601  29
Ce
1213  65
Pr
141  11
Nd
365  9
3
4
5
4
5
5
5
1410
160
750
580
1230
-
Trace elements
B
92
Al
77 19
Ti
39  6
Ga
45  9
As
40  1
Nb
13  1
Sb
6.1  1.5
Te
2.9  2.3
W
84  8
Pb
1.32  0.23
3
5
5
5
4
5
5
4
5
5
12
80
37
Mn
36
(Cert.values (%) : Cr-26.72;Ni-30.82;Mo-3.55)
Cont`d
Round-Robin test. Concentrations of ultra-trace
elements in a high alloy steel - JK 37.
n = number of participating laboratories; concentration in g/g
Ultra-trace elements
Be
Pd
Ag
Ba
Ta
Ir
Pt
Tl
Bi
<0.1
<1
<0.4
<1
<0.2
0.20  0.03
<0.2
<0.2
0.33  0.13
n
4
2
4
4
5
5
5
4
5
Trace or ultra-trace elements ?
Ca
Zn
Se
<12
<5
<10
4
2
2
Cert.value
ICP-TOFMS - LECO Renaissance
Laser Ablation System
CETAC LSX-200 plus
Instrument installation
ICP-TOFMS
Flight tube
LECO - Renaissance
Typical fly times for ten elements
Element Fly time (ns)
Li7

Mg 24

Ti48
Y89

In115

Ba138

Ce140

Pb208

Bi 209

U 238
6750
12150
17022
23020
26110
28558
28762
34972
35056
37382
ICP-TOFMS
Analysis of wet-digested low alloy steel samples
Concentrations given in µg/g (ppm)
Ele ment
Ti
Zn
Ga
Nb
Sn
Sb
Te
La
Ce
Pr
Nd
Gd
Ta
Ir
Pt
Tl
Pb
Bi
U
HO 047Ovako Steel AB
Ball Bearing Steel
n=8
Value determin.
14.0  0.3
16.2  1.2
27.0  0.2
46.9  0.9
0.28  0.04
<1
<0.076
<0.045
<0.028
<0.048
<0.22
<0.048
<0.068
<0.14
<0.059
0.79  0.03
<0.047
<0.028
ECRM 090-1
BAS
Low Alloy Steel
n=7
Value determ.
Cert. value
19.7  0.3
20.9
21.6  1.5
22.8
22.0  0.2
4.3
4.69  0.06
44.0  0.04
9.0
8.14  0.08
<1
<2
<0.076
<0.045
<0.028
<0.048
<0.22
0.061 0.010
0.08  0.01
0.12  0.04
<0.059
<1
23.9
23.6  0.3
<0.2
<0.028
ICP-TOFMS
Analysis of wet-digested high alloy steel samples
Concentrations given in µg/g (ppm)
Ele ment
Ti
Ga
Nb
Sn
Sb
Te
La
Ce
Pr
Nd
Gd
Ta
Ir
Pt
Tl
Pb
Bi
U
SDN 1021
AB Sandvik Steel
High alloy steel
n=4
Value determined
89.4  0.8
27.9  1.3
35.2  0.9
11.1  0.1
0.98  0.07
<1
18.4  0.5
130  5
14.8  0.1
19.7  0.3
1.5  0.1
<0.048
<0.068
<0.14
<0.059
<0.059
0.10  0.01
<0.028
CRM JK 37
Jernkontoret/SIMR
High Alloy Steel
n=9
Value determined Cert. value *
38
42.2  0.2
30
28.8  0.4
12
18
14.5 0.2
5
5.6  0.1
<1
<2
371
357  12
1230
1170  40
129
103  5
347
306  7
68
59  1
<0.2
0.051  0.004
0.2
0.23  0.01
0.1
0.14  0.01
<0.059
<0.1
1
1.32  0.02
0.3
0.32  0.01
0.09
0.087  0.006
*Figures in italics refer to earlier determinations carried out by five different laboratories
Laser Ablation
Copper scanning- spot size 200 µm
Laser Ablation
Analysis of Copper
Copper samples:
BAM 381 BAM 383
BAM 382 BAM 385
All BAM samples above have been
determined in a traditional wet chemical way
by ICP-TOFMS
LASER measurements:
Calibration with BAM 381, 384 and 385
Internal standard Sn118 or Ag107
Determination of BAM 383
LA-ICP-TOFMS and ICP-TOMS
Comparison of trace element determinations
Element
Ag1 0 9
Bi 2 0 9
Cd1 1 4
Co5 9
Mg2 6
Mn5 5
Sb1 2 1
Sn1 1 8
Te 1 2 6
Laser
ppm
5.15
1.18
1.73
1.82
2.86
1.37
1.04
4.74
1.46
Traditional
ppm
4.86
1.08
1.67
1.44
2.64
2.08
1.29
4.60
1.52
Laser Ablation
Analysis of Steel
Steel Samples:
JK 1C
ECRM 090-1
EZRM 179-2
HOØ47 (Ovako)
Pure Iron
Carbon Steel
Tool Steel
Ball Bearing Steel
Calibration with:
JK 1C, ECRM 090-1, EZRM 179-2
Internal standards:
Samples analysed:
Ga and Ni
HOØ47 (Ovako)
Laser Ablation
Comparison of determinations
HOØ47 (Ovako)
Element
Laser
OES
%
%
Cu
0,075
0,07
Cr
1,28
1,43
Ni
0,07
0,06
Mo
0,016
0,02
Laser Traditional
ppm
ppm
Zn
16,3
16,2
Laser Ablation
Analysis of Zircaloy
Zircaloy samples:
9 authentic samples
Calibration with:
Jaeri-Z11 and two in-door samples
Internal standards:


Zr90O16  ( Pd106
) and Zr91O16  ( Ag107
)
Laser Ablation - Zircaloy samples
Calibration for Cr50 with internal standard
Zr90O16
Laser Ablation - Zircaloy samples
Calibration for Cr50 with no
internal standard
Laser Ablation - Zircaloy samples
Comparison of trace element determinations
Sample
A
B
D
E
G
H
I
Jaeri-Z11
Cr50
meas.
0.123
0.121
0.117
0.119
0.118
0.121
0.124
0.132
0.11
0.129
0.103
0.129
0.117
0.123
0.041
0.048
Ni58
meas.
0.061
0.061
0.06
0.066
0.002
0.007
0.062
0.069
0.051
0.063
0.062
0.070
0.06
0.065
0.021
0.023
Co59
meas.
<5
5.0
6
5.1
<5
4.9
<5
5.1
<5
5.1
8
5.1
7
5.1
6
6.0
Cu63
meas.
<10
12.1
<10
9.4
<10
9.1
10
15.1
<10
11.5
15
10.1
14
8.5
40
40.2
Hf176
meas.
50
51.7
50
53.2
50
61.6
55
56.5
50
57.6
50
52.8
50
54.6
71
73.4
Ti48
meas.
<5
0.4
<5
8.8
<5
8.8
6
6.9
5
9.9
9
2.7
6
4.4
28
27.6
U238
meas.
< 0.5
0.05
< 0.5
0.06
< 0.5
0.18
< 0.5
0.15
< 0.5
0.2
< 0.5
0.12
< 0.5
0.09
0.8
0.74
Pb208
meas.
2
2.2
2
2.4
2
2.5
2
2.3
2
2.1
2
2
2
12
12.8
Laser Ablation
Depth profiling analysis of Al
Parameters:
Spot size
Energy
Frequency
Integ. time
Data points
Al-layer content:
(100 µm thickness)
50 µm
3.8 mJ
20 Hz
102 ms
1760 / isotope
Si 7.4 ± 0.2 %
Mn <0.01 %
Mg <0.01 %
Pb
0.01 %
Ti
<0.01 %
Laser Ablation
Depth profiling graph for
two Al-layers
3500
Mg
Mn
Pb
Si
Ti
3000
Counts
2500
2000
1500
1000
500
0
0
20
40
60
80
100
Time (s)
120
140
160
180
Three coating layers of a cutting tool
Thickness of coating layers according to:
- TiN
1 µm
- Al2O3
4 µm
- Ti (C, N) 1 µm
Laser Ablation - Transient signals of the
elements Al, Co, Ti and W on a cutting tool
Al (Analog)
Co (Analog)
Ti (Analog)
W (Analog)
Instrumental signal (LOG mV)
1000
100
10
0
20
40
60
80
100
120
Time (s)
Al (Analog)
Co (Analog)
Ti (Analog)
W (Analog)
Instrumental Signal (LOG mV)
1000
100
10
0
10
20
30
40
50
60
70
Time (s)
80
90
100
110
120
Laser Ablation - Depth profile curve for Hg
of an old zinc coated steel sheet
Hg (Counts)
BV 232
800
Signal (counts)
600
400
200
0
40
60
80
100
Time (s)
Signal (counts)
800
120
Hg (Counts)
BV 232
Thickness of
Hg-layer - 16.3µm
600
400
200
0
0
5
10
15
Djup (µm)
20
25
Laser Ablation - Depth profile curve for Hg
of a scrap steel sample
Hg (Counts)
200
Weldox 9601
180
Signal (counts)
160
140
120
100
80
60
40
20
0
40
60
80
100
Tid (s)
120
Hg (Counts)
200
Weldox 9601
180
Signal (counts)
160
Thickness of
Hg-layer - 3.8 µm
140
120
100
80
60
40
20
0
0
5
10
15
Djup (µm)
20
25
30
Conclusions
LA-ICP-TOFMS vs ICP-TOFMS:
- a fast method compared with wet chemical
analysis
- a fast method for depth profile analysis
- a tool for trace element
determinations in steel and metals
- a promising tool for determination of
inhomogenieties (inclusions) in steel
and metals