347 is a niobium-containing austenitic stainless steel and 347H is its high carbon version.From the composition, 347 can be seen as 304 [TJC 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[TJC 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[TJC 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[TJC 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[TJC 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, [TJC 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,[TJC STEEL] hot gas pipe of turbine compressor and parts working under low load and temperature not exceeding 850℃.