Hastelloy C、UNS N10002

HastelloyC overview

HastelloyC alloy is a high temperature and corrosion resistant alloy, containing a large amount of Cr, Mo and other elements, and has a single-phase austenite structure. Corrosion-resistant alloy with many excellent properties, has good resistance to oxidative and medium reducing corrosion. It has excellent resistance to stress corrosion cracking and good local clothing resistance. It has satisfactory corrosion resistance in many chemical process media, including highly etched inorganic acid solutions, chlorine and various media containing chlorides, Chlorine, formic acid and acetic acid, sea water and brine, etc.

 

HastelloyC chemical composition

%	C	Mn	P	S	Si	Cr	Mo	Ni	W
Min.						14.5	15.0	margin	3.0
Max.	0.08	1.00	0.040	0.030	1.0	16.5	17.0		4.5

 

Physical properties of Hastelloy C:

Density	9.24g/cm3
Melting point	1330-1380℃

 

HastelloyC minimum mechanical properties:

Alloy and condition	tensile strength Rm N/mm2	yield strength RP0.2N/mm2	Elongation A5 %
Hastelloy C	690	310	40

 

Hastelloy C alloy has the following characteristics

1. Control the minimum content of iron and chromium to prevent the formation of β phase Ni4Mo.

2. Excellent corrosion resistance to reducing environment.

3.Excellent resistance to moderate concentration of sulfuric acid and many non-oxidizing acids.

4. Very good resistance to chloride ion stress corrosion cracking (SCC).

5. Excellent resistance to various organic acids.

 

Hastelloy C metallographic structure:

HastelloyC has a face-centered cubic lattice structure. By controlling the iron and chromium content to a minimum, processing brittleness is reduced and the precipitation of the Ni4Mo phase at 700-870 ° C is prevented.

 

Hastelloy C corrosion resistance:

The nickel and molybdenum alloy HastelloyC has extremely low carbon and silicon content, which reduces the precipitation of carbon and other impurity phases in the heat-affected zone of the weld, so its weld has sufficient corrosion resistance. Alloy Hastelloy C-2 has good corrosion resistance in reducing media, such as hydrochloric acid solutions at various temperatures and concentrations. It also has good corrosion resistance in medium concentration sulfuric acid solution (or containing a certain amount of chloride ion). It can also be used in acetic acid and phosphoric acid environments. Alloy materials can have the best corrosion resistance only when the metallographic state and pure crystal structure are suitable.

 

Hastelloy C application areas are:

The alloy HastelloyC has a wide range of applications in the fields of chemistry, petrochemicals, energy manufacturing, and pollution control, especially in industries such as sulfuric acid, hydrochloric acid, phosphoric acid, and acetic acid.

 

HastelloyC processing

Thermal processing

1. The hot processing temperature range is 1200 ℃ ～ 950 ℃, and the cooling method is water cooling or rapid air cooling.

2. To ensure the best anti-corrosion performance, heat treatment should be performed after hot working, and the workpiece should be directly added

Heat treatment furnace.

Cold working

1. The work hardening rate is greater than austenitic stainless steel, so the processing equipment needs to be selected. The workpiece should be in the solution heat treated state, and there should be intermediate annealing during the cold rolling process

2. If the cold rolling deformation is greater than 15%, a second solution treatment is required for the workpiece.

 

HastelloyC welding process

Suitable for welding using any traditional welding process, such as tungsten electrode inert gas shielded welding, plasma arc welding, manual sub-arc welding, metal extremely inert gas shielded welding, molten extremely inert gas shielded welding

Special alloy materials commonly used in the chemical industry:

Stainless steel: 253MA, 316L, 353MA, 654SMO, 904L, etc.

Nickel-based alloys: Alloy 31, Alloy 59, Hastelloy B, Hastelloy C, Hastelloy C-276, etc.

Corrosion-resistant alloys: NS112, NS322, NS333, NS335