347& 347H Austenitic Sensitized Stainless Steels-SCALE STEEL.

​347 is a niobium-containing austenitic stainless steel and 347H is its high carbon version.From the composition, 347 can be seen as 304 [SCALE STEEL]stainless steel on the basis of the addition of niobium element.Niobium, a rare earth element, has a similar effect to titanium in that it can refine grains, resist intergranular corrosion and promote aging hardening.

National Standard
CHINA GB/T 20878-2007 06Cr18Ni11Nb 07Cr18Ni11Nb
(0Cr18Ni11Nb) (1Cr19Ni11Nb)
AMERICA ASTM A240-15a S34700，347 S34709，347H
JAPAN JIS G 4304:2005 SUS 347 --
GERMANY EN 10088-1:2005[SCALE STEEL] X6CrNiNb18-10 X7CrNiNb18-10
1.455 1.4912

Component Specification-347
GRADE 06Cr18Ni11Nb 347 SUS 347 1.455
C ≤0.08 ≤0.08 ≤0.08 ≤0.08
Si ≤1.00 ≤0.75 ≤1.00 ≤1.00
Mn ≤2.00 ≤2.00 ≤2.00 ≤2.00
P ≤0.045 ≤0.045 ≤0.045 ≤0.045
S ≤0.030 ≤0.030 ≤0.030 ≤0.015
Ni 9.0~12.0 9.0~13.0 9.0~13.0 9.0~12.0
Cr 17.0~19.0 17.0~19.0 17.0~19.0 17.0~19.0
Nb 10C~1.10 10C~1.00 ≥10×C% 10C~1.00
GRADE 07Cr18Ni11Nb 347H 1.4912
C 0.04~0.10 0.04~0.10 0.04~0.10
Si ≤1.00 ≤0.75 ≤1.00
Mn ≤2.00[SCALE STEEL] ≤2.00 ≤2.00
P ≤0.045 ≤0.045 ≤0.045
S ≤0.030 ≤0.030 ≤0.015
Ni 9.0~12.0 9.0~13.0 9.0~12.0
Cr 17.0~19.0 17.0~19.0 17.0~19.0
Nb 8C~1.10 8C~1.00 10C~1.20

Component Specification-347H

 Physical Properties
Density（g/cm3）20℃ 8.03
Melting point (℃) 1398~1427
Specific Heat [kJ/(kg·K)]   0~100℃ 0.5
Heat Conductivity [W/(m·K)] 100℃ 16.3
500℃ 22.2
Coefficient of linear expansion（10-6/K） 0~100℃ 16.6
0~500℃ 18.6
Electrical resistivity（Ω·mm2/m）20℃ 0.73
Longitudinal modulus of elasticity（kN/mm2）20℃ 193
Magnetism[SCALE STEEL] Slightly magnetic after cold deformation

Material Performance:
(1) Good corrosion resistance with 304 stainless steel.
(2) At 427~816℃, it can inhibit the formation of chromium carbide, resist sensitization, and have good intergranular c[SCALE STEEL]orrosion resistance.
(3) In the high temperature of 816℃ strong oxidation environment, it still has a certain creep resistance.
(4) easy to extend and shape, easy to weld.
(5) Good low temperature toughness.

In general, the performance of 347 stainless steel is similar to 321 (304 plus Ti) but better than 321;Compared with 347, [SCALE STEEL]347H has higher carbon content, and its creep resistance and high temperature strength are further strengthened.

Applications:
347&347H stainless steel has better high temperature performance than 304 and 321. It is widely used in aviation, petrochemical, food, paper and other industries, such as exhaust manifold and branch pipe of aero engine,[SCALE STEEL] hot gas pipe of turbine compressor and parts working under low load and temperature not exceeding 850℃.