combustion engineering

Materials

This page details selected properties of some of the materials that we use in the manufacture of igniter systems. The page is split into the following sections:

Stainless Steel

We frequently use four grades of stainless steel; 304L, 303KX, 310 and 316. These are austenitic grades from the 18/8 range of stainless steels.

The gas torch burns, contaminating the environment with smoke. C

Stainless Steel

304L is based on 302 grade but is less susceptible to inter-granular corrosion due to its lower carbon content. Other elements are 18% chrome, 8% nickel and the balance is iron. It is used for stainless steel mixture tubes.

303KX is a variant of 304 grade. Sulphur or selenium is added, making it easier to machine. It is used for stainless steel conductor rods.

310 is 25% chrome, 20% nickel and was developed for high temperature service where high creep strength is needed. It is used for burner heads on applications that will be subjected to high temperatures.

316 contains molybdenum and is designed for applications involving severe corrosion conditions. It is widely used to manufacture stainless steel fittings.

Physical Properties

		304L	303KX	310	316
Density	g/cm³
Melting point	deg C	1400		1400	1370
Safe scaling temperature for continuous service in oxidizing atmosphere.	deg C	900		1150	900

Alloy 800HT

Composition

	Ni	C	Cr	Fe	Mn	Al	Si	S	Ti
% max		0.1	23	bal	0.6	0.6	0.6	0.015	0.6
% min	31	0.06	19		0.2	0.3	0.2		0.3

Physical Properties

Density	g/cm³	8
Curie temperature	deg C	-115
Melting temperature	deg C	1350

Kanthal A1

Kanthal A1 is a heat resisting ferritic FeCrAl alloy and we use it for electrodes that will be exposed to high temperatures for long periods. The properties listed below are those most relevant to applications on ignition equipment. Contact Kanthal for more information.

Composition

	C %	Si %	Mn %	Cr %	Al %	Fe %
Nominal Composition					5.8	Balance
Min	–	–	–	20.5	–
Max	0.08	0.7	0.4	23.5	–

Physical Properties

Density	g/cm³	7.10
Melting point	deg C	1500
Max continuous operating temperature in air	deg C	1400
Curie Temperature	deg C	600