STAINLESS
Heat-Resistant Austenitic
Stainless Steel
（ASTM：UNS 31060）
（NSSMC-NAR-AH-4）
http://www.nssmc.com/
2-6-1 Marunouchi, Chiyoda-ku,Tokyo 100-8071 Japan
Tel: +81-3-6867-4111
Heat-Resistant Austenitic Stainless Steel
S004en_01_201212f
© 1997 , 2012 NIPPON STEEL & SUMITOMO METAL CORPORATION
Alloy Design・Features
❶
Main Use Applications
1 Parts requiring heat resistance in Industrial Furnaces, Heat-treating Furnaces, Power Plants and
Alloy design of NSSMC-NAR-AH-4
Oxidation Resistance・ Creep Rupture
Erosion Resisitance
Strength
High Cr≧22.5%
Solid solution strengthening：
Addition of N
Addition of rare
earth metals
Grain boundary strengthening：
Addition of B
Chemical Plants.
Microstructural
Stability・
Cost Saving
Addition of N
2 Fuel cell reforming Tube.
Weldability
Decrease of Si
Optimization of
Creq / Nieq
Grain size control
3 Auto parts（Exhaust Manifold etc.）.
4 Substitute for SUS310S. Especially suited for material requiring high-temperature mechanical strength.
Specification and Equivalent Specification
Physical Properties
●ASTM A240, A213　●UNS S31060
●ASME Code Case 2430
（ASME Section Ⅰ & Ⅷ, Div.1 Boiler and Pressure Vessel）
❶ Specification
Table 1 : Chemical Composition (wt％)
0.3%Si -0.07%C -23%Cr -11%Ni -0.2%N -La+Ce -B
❷ Superior High Temperature Properties
Designation
C
NSSMC-NAR-AH-4
0.05〜
0.10
0.05〜
0.10
UNS S31060
（for reference）
SUS 310S
≦0.08
Si
Mn
P
S
≦1.00
≦1.00
≦0.040
≦0.030
≦0.50
≦1.00
≦0.040
≦0.030
≦1.50
≦2.00
≦0.045
≦0.030
Cr
Ni
N
other elements
22.00〜
24.00
22.00〜
24.0
22.00〜
26.00
10.00〜
12.00
10.00〜
12.5
19.00〜
22.00
0.18〜
0.25
0.18〜
0.25
La＋Ce
0.03〜0.07
La＋Ce
0.025〜0.070
B0.001〜0.010
─
─
●Higher tensile strength and creep strength at high temperature than SUS310S（JIS G4303）
.
●Excellent oxidation resistance at 900〜1000℃ superior to SUS310S.
●Superior structure stability after long-term exposure to high temperature（700〜900℃）
,
without a drastic drop in toughness like SUS310S.
❸ Superior Weldability
●Lower sensitivity of weld hot cracking than SUS310S, especially favorable for thick plates
❷ Physical Properties
Table 2 : Density, Specific Heat, Thermal Conductivity and Thermal Diffusivity
Designation
Density（g/cm3）
NSSMC-NAR-AH-4
UNS S31060
7.88
502
13.8
0.036
8.03
502
14.2
─
（for reference）
SUS 310S
Specific Heat（J/Kg・K）Thermal Conductivity（W/m・K） Thermal Diffusivity（cm2/sec）
welding.
Table 3 : Linear Expansion Coefficient
❹ Cost Saving
Temperature（℃）
30-100
30-200
30-300
30-400
30-500
30-600
30-700
30-800
Linear Expansion（×10−6/℃）
15.7
16.2
16.8
17.1
17.4
17.7
18.1
18.5
30-900 30-1000
18.7
19.1
●Reasonably designed chemical composition as compared with SUS310S.
Table 4 : Poisson' s ratio
Notice: While every effort has been made to ensure the accuracy of the information contained within this publication, the use of the information is at the reader’ s risk and no warranty
is implied or expressed by Nippon Steel & Sumitomo Metal Corporation with respect to the use of the information contained herein. The information in this publication is subject to
change or modification without notice. Please contact the Nippon Steel & Sumitomo Metal Corporation office for the latest information.
Please refrain from unauthorized reproduction or copying of the contents of this publication.
The names of our products and services shown in this publication are trademarks or registered trademarks of Nippon Steel & Sumitomo Metal Corporation , affiliated companies,
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trademarks of their respective owners.
1
Temperature（℃）
RT
450
500
600
700
800
900
1000
Modulus of Elasticity（GPa）
188
158
154
146
138
130
128
119
Poisson' s ratio
0.260
0.260
0.260
0.262
0.263
0.263
─
─
2
❸ Mechanical Properties
❸ High-temperature Properties
Table 5 : Mechanical Properties
NSSMC-NAR-AH-4
UNS S31060
（for reference）
SUS 310S
Elongation（％）
Hardness（HRB）
≧280
≧600
≧40
≦95
≧205
≧520
≧40
≦90
Properties of NSSMC-NAR-AH-4
300
0.2% Yield Strength/Tensile Strength
2
（N/mm ）
0.2% Yield Strength（N/mm2） Tensile Strength（N/mm2）
0.2% Yield Strength/Tensile Strength
2
（N/mm ）
Designation
900
：AH-4
：SUS 310S
200
Tensile Strength
100
0.2% Yield Strength
0
800
900
Test Temperature（℃）
800
0.2% Y.S.
T.S.
700
600
500
400
300
200
0
1000
SUS 310S
AH-4
Fig.2 Tensile properties at room
temperature
Fig.1 Tensile properties at high
temperature
150
❶ Chemical Composition
50
900℃ 1000℃Designation
30
SUS 310S
Si
Mn
P
S
Cr
Ni
N
La＋Ce
B
NSSMC-NAR-AH-4
0.07
0.31
0.48
0.021
0.001
23.11
10.95
0.197
0.03
0.003
（for reference）
SUS 310S
0.05
0.58
1.21
0.023
0.001
24.63
20.25
0.024
─
─
Impact Value
（J/cm2）
C
Stress
（N/mm2）
Designation
10
10
10
Time to rupture（h）
2
3
5
1000
❹ Resistance to high-temperature oxidation
or coarser, as measured by Test
Methods E112
0
（ Thickness ≧ 6mm）
100
cycles
200
Weight change by oxidation
2
（g/m ）
900℃
0
-100
0
-100
300
400
40
SUS 310S
AH-4
1000℃
SUS 310S
AH-4
（25minutes heating-5minutes air cooling）
Fig.5 Cyclic oxidation test result in the air
3
800
Aging temperature（℃）
Fig.4 Charpy impact properties after
aged at 700～900℃
Weight gain by oxidation
2
（g/m ）
● Grain size：Average grain size of ASTM No.7
SUS 310S
0
600
10
4
Fig.3 Creep rupture properties
Microstructure
● Austenitic structure
50
AH-4
5
10
Photo 1. Typical microstructure after
solution heat treated
Aging time：3000h
100
Table 6 : Typical Chemical Composition (wt%)
❷
Test piece：2mm V-notch, half size
Test temperature：room temperature
AH-4
30
1000℃
900℃
in air
20
10
0
AH-4
SUS 310S
Fig.6 Continuous oxidation test result（200h）
4
❺ Resistance to high-temperature erosion
600
Designation
AH-4
10
SUS 310S
Blasted speed：5m/s
Temp.：900℃
Abrasives：silicate sand
ε＝2%
400
2000
200
1000
0
50
0
100
0.1
0.3
5
600
1000
（Cold rolling）
No crack
↓
0
AH-4
Time（h）
Fig.7 Erosion test result（900℃）
（n＝2）
Thickness
（mm）
Maximum depth of
thickness loss
Total crack length
（mm）
Weight loss
（mg）
3000
Weight loss
Maximum depth of thickness loss
（μm）
4000
Available Sizes
❻ Weldability
SUS 310S
3.0
1219
1524
2000
6.0
（Hot rolling）
32.0
40.0
Fig.8 Hot cracking test result
（Longi Varestraint test）
2,000
1,000
3,000
Width（mm）
❼ Creep Rupture Strength of Welded Joint
900℃ 1000℃
50
Available maximum length：6,000mm
：Range of consultation
Consult us for custom-made dimensions.
AH-4
Base Metal
Stress
（N/mm2）
30
Welded Joint
10
5
10
10
10
Time to rupture（h）
2
3
Fig.9 Creep rupture test
result of welded joint
4
10
5
Base metal thickness：20mm
Welding process：GTAW
Welding consumable：WEL Auto TIG AH-4（1.2φ）
❽ Welding Consumables
●Supplier : Nippon Welding Rod Co., Ltd.
[URL] http://www.nihonwel.co.jp/
[e-mail] info@nihonwel.co.jp
5
For TIG welding
For SMA welding
WEL TIG AH-4
1.2, 1.6, 2.0, 2.4, 3.2mmφ
WEL Auto TIG AH-4
1.2, 1.6mmφ
WEL AH-4
2.6, 3.2, 4.0, 5.0mmφ
6