347Triton Alloys  stocks Alloy 347 stainless steel plate in thicknesses from 6mm to 40mm. A high carbon version, Alloy 347H (UNS S34709), can also be ordered in the same thickness range.Alloy 347 (S34700) is a stabilized stainless steel which offers as its main advantage an excellent resistance to inter granular corrosion following exposure to temperatures in the chromium carbide precipitation range from 800 to 1500°F (427 to 816°C). Alloy 347 is stabilized by the addition of columbium and tantalum.

Alloy 347 stainless steel is also advantageous for high temperature service because of its good mechanical properties. Alloy 347 stainless steel offers higher creep and stress rupture properties than Alloy 304 and, particularly, Alloy 304L, which might also be considered for exposures where sensitization and inter granular corrosion are concerns.

347 stainless steel has a high resistance to prolonged heat and corrosion making it well suited for engine, power generation, welded fabrications and other high heat applications. 347 stainless steel offers good mechanical properties with higher creep and stress rupture characteristics than other grades, such as 304. 347 stainless steel is also advantageous in applications that require omission of the annealing process after welding.

 

Specification

Grade

UNS No

Old British

Euronorm

Swedish SS

Japanese JIS

BS

En

No

Name

347

S34700

347S31

58G

1.4550

X6CrNiNb18-10

2338

SUS 347

 


Standards

EURONORM 1.4550 X6CrNiNb18-10
AFNOR Z6 CN Nb 18-10
DIN WW1.4550
ASTM A 240 – TP 347

 

Chemical Composition

Grade

C

Mn

Si

P

S

Cr

Mo

Ni

N

Other

347

min/max

0.08

2.00

0.75

0.045

0.030

17.0

19.0

-

9.0

13.0

-

Nb=10(C+N)

1.0

 

Mechanical Properties

Grade

Tensile Strength (MPa) min

Yield Strength 0.2% Proof (MPa) min

Elongation (% in 50mm) min

Hardness

Rockwell B (HR B) max

Brinell (HB) max

347

515

205

40

92

201

 

 Impact Values

°C (°F) -196 (-320) +20 (68)
KCV (J/cm2)
Typical
175 225
KCV (J/cm2) Minimum 100 150

 


Physical Properties

Grade Density Modulus of Elasticity in Tension Melting Range
g/cm3 lb/in3
347
7.96
0.288
28 x 106 psi193 GPa
1398-1446°C2550-2635°F

 


Mean Coefficient of Linear Thermal Expansion

Temperature Range Coefficients
°C °F cm/cm/°C in/in/°F
20-100
68-212
16.6 x 10-6
9.2 x 10-6
20-600
68-912
18.9 x 10-6
10.5 x 10-6
20-1000
68-1832
20.5 x 10-6
11.4 x 10-6

 


Thermal Conductivity

Temperature Range W/m·K Btu · in / hr · ft2 · °F
°C °F
20-100
68-212
16.3
112.5
20-500
68-932
21.4
147.7

 


Specific Heat

Temperature Range J/kg K Btu/lb · °F
°C °F
0-100
32-212
500
0.12

 

Corrosion Resistant

Quality corrosion tests guaranteed (special request may be discussed)
TEST
Other name
Corrosion (1)
Results
ASTM A 262 A
Intergranular
Step or dual structure
ASTM A 262 B
STREICHER
Intergranular
Not recommended
ASTM A 262 C
HUEY
Intergranular
Not recommended
ASTM A 262 E DIN 50914
STRAUSS
Intergranular
No cracking after bending
Not recommended
ASTM G48 A
Pitting
(typical CPT <5°C-41°F)
Not recommended
ASTM G48B
ASTM G78
Crevice
(typical CCT ≤ 0°C-32°F)

 

To find out more about Triton Alloys Inc Services and our Range of “ Grade 347 & 347H Stainless Steel” which we can supply directly to you, Click Here to Contact Us.