C-22 / N06022 High Performance Alloys Bar / Pipe And Strip Good Resistance To Wet Corrosion

High performance Alloy 22 (C-22, N06022) bar, pipe, strip, forging, wire for chemical and petrochemical processing

1 PRODUCT

High performance Alloy 22 (alloy C-22, UNS N06022) semi-products for chemical and petrochemical processing

Alloy 22 standard semi-product forms include sheet, strip, plate, round bar, flat bar, forging, hexagon, ring, disc and wire.

2 EQUIVALENT DESIGNATION

Alloy C-22, UNS N06022, W.Nr. 2.4602, NiCr21Mo14W(DIN), NiCr21Mo14W3(ISO), Inconel® alloy 22, VDM® Alloy 22, Nicrofer 5621 hMoW, Hastelloy® C-22®

3 OVERVIEW

Alloy 22 is a fully austenitic advanced corrosion-resistant alloy that offers resistance to both aqueous corrosion and attack at elevated temperatures. This alloy provides exceptional resistance to general corrosion, pitting, crevice corrosion, intergranular attack, and stress corrosion cracking.

Alloy 22 is nickel-base and typically contains 22% chromium, 14% molybdenum, 3% tungsten and extremely low carbon and silicon content. Iron is normally limited to less than 3%. The alloy’s high content of chromium gives it good resistance to wet corrosion by oxidizing media (e.g., nitric acid and ferric and cupric salts). Its contents of molybdenum and tungsten give the alloy resistance to wet reducing media (e.g., sulfuric and hydrochloric acids). Alloy 22 exhibits excellent resistance to corrosive attack by seawater under stagnant and flowing conditions.

4 APPLICATION

Alloy 22 has a broad field of application in the chemicals and petrochemicals industry and is used for components in organic processes that contain chloride and for catalytic systems. The material is especially effective in hot, contami- nated mineral acids, solutions, organic acids (such as formic acid and acetic acid) or sea water.

Other fields of application are:

Acetic acid production

Pharmaceuticals industry

Fine chemicals

5 CHEMICAL COMPOSITION (wt%):

Table 1 (wt%) as per ASTM B575

*Reference to the ‘balance’ of a composition does not guarantee this is exclusively of the element mentioned but that it predominates and others are present only in minimal quantities.

Table 2 Typical compositions of the Ni-Cr-Mo-W corrosion resistant alloys

This table compares the combined alloying content (Cr+Mo+W+Nb) of Alloy 22 with other similarly alloyed materials.

6 PHYSICAL PROPERTIES

Density at 20°C: 0.311 lb/in³ (8.61g/cm³)

Melting range: 1351-1387°C (2464-2529°F)

Specific Heat: 0.091Btu/lb•°F (381J/kg•°C)

Permeability at 200 oersted (15.9 kA/m): ≤1.001

Electrical Resistivity: 730.7 ohm•circ mil/ft, 1.215 microhm•m

Young’s Modulus (Dynamic) 30.3x10³ ksi. (209 GPa)

Coefficient of Expansion 70-200°F,6.90 x 10⁶ in/in•°F (21-193°C, 12.42 m/m•°C)

7 MECHANICAL PROPERTIES

The following minimum values at room and increased temperatures apply to the solution-annealed condition for longitudinal and traverse test samples of the specified dimensions. The properties for larger dimensions must be agreed upon separately.

Table 3 Mechanical properties at room and elevated temperatures. Minimum values according to VdTÜV Sheet 479

Table 4 Mechanical properties at room temperature. Minimum values according to VdTÜV Sheet 479

ISO V-notch impact energy KV

1)Average value of 3 samples. Only one value may fall below the minimum average value, and by no more than 30%. The values also apply for the heat affected zones in welded joints.

2)These values only apply for normal samples according to DIN EN ISO 148-1. For undersized samples according to DIN EN ISO 148-1, the minimum values indicated for the notch impact toughness must be reduced in a manner that is linear to the sample cross-section in the gap. For undersized samples <5mm according to DIN EN ISO 148-1, the values for the individual case must be coordinated with the manufacturer separately.

8 CORROSION RESISTANCE

Due to the extremely low carbon and silicon concentrations, Alloy 22 has no propensity for grain boundary disper- sions in hot forming or welding. This alloy can therefore be used in many chemical processes with both oxidizing and reducing media when welded. The high chrome, molybdenum, and nickel concentrations make the alloy resistant to chlo- ride ion attacks. The tungsten concentration further increases this resistance. Alloy 22 is resistant to chlorine gas, hypochlorite, and chlorine dioxide solutions such as those that can be encountered in the cellulose industry. The alloy is characterized by excellent resistance to concentrated solutions of oxidizing salts (such as iron III and copper chloride)

9 MICROSTRUCTURE

Alloy 22 has a cubic, face-centered crystal structure.

10 WORKING INSTRUCTION

Alloy 22 is readily fabricated by standard procedures for nickel alloys. It can be easily formed both hot and cold and can also be machined.

Heating

The material can be hot-formed in a temperature range between 1100 and 900°C (2012°F-1652°F) with subsequent rapid cooling down in water or air. Heat treatment after hot forming is recommended in order to achieve optimal properties. For heating up, workpieces should be placed in a furnace that is already heated up to the target value.

Cold forming

Alloy 22 has higher work hardening rate than other austenitic stainless steels. This should be taken into account when selecting forming equipment. The workpiece should be in the solution-annealed condition. Intermediate annealing is necessary for major cold forming work. For cold forming above 15%, new solution annealing must be conducted.

Heat treatment

Solution annealing should take place at temperatures between 1105 and 1135°C (2021-2075°F).

Cooling down should be accelerated with water to achieve optimum corrosion properties. Fast air cooling can also be carried out at thicknesses of less than approx. 1.5 mm.

Machining

Alloy 22 should be machined in the solution-annealed condition. Because of the considerably elevated tendency toward work hardening in comparison with low-alloy austenitic stainless steels, a low cutting speed and a feed level that is not too high should be selected and the cutting tool should be engaged at all times. An adequate chip depth is important in order to cut below the previously formed strain-hardened zone. An optimal heat dissipation by using large quantities of suitable, preferably aqueous, cold forming lubricants has considerable influence on a stable machining process.

11 STANDARD SPECIFICATION

Alloy 22 is approved for construction of pressure vessels and components under the ASME Boiler and Pressure Vessel Code Section VIII, Division 1 for service up to 1250°F (677°C). The alloy is also approved by VdTÜV under Werkstoffblatt 479.

Rod, Bar, Wire and Forging Stock

ASTM B462 Rod, Bar and Forging Stock

ASTM B564 / ASME SB564 Forgings

ASTM B574 / ASME SB574 Rod, Bar and Wire

ASME Code Case 2226

ASME Code Case N-621

ISO 9723

ISO 9724

ISO 18274 Wire

DIN 17752 Rod & Bar,

DIN 17753 Wire

DIN 17754 Forgings

NACE MR 0103/ISO 17945

NACE MR 0175/ISO 15156

VdTÜV 479

Plate, Sheet

ASTM B575 / ASME SB575

ASTM B906 / ASME SB906

ASME Code Case 2226

ASME Code Case N-621

ISO 6208

ISO 9722

DIN 17750

NACE MR 0103/ISO 17945

NACE MR 0175/ISO 15156

VdTÜV 479

Strip

ASTM B575 / ASME SB575

ISO 6208

ISO 18274

NACE MR0175/ISO 15156

Pipe and Tube

ASTM B619 / ASME SB619

ASTM B775 / ASME SB775 Welded Pipe

ASTM B622 / ASME SB622

ASTM B829 / ASME SB829 Seamless tube

ASTM B626 / ASME SB626

ASTM B751 / ASME SB751 Welded Tube

ASME Code Case 2226

ASME Code Case N-621

ISO 6207

DIN 17751

Welding Products

INCONEL Filler Metal 622

AWS A5.14

ERNiCrMo-10

INCONEL Welding Electrode 622

AWS A5.11

ENiCrMo-10

Other Product Forms

ASTM B366 / ASME SB366 Fittings

DIN 17744 Composition

12 COMPETITIVE ADVANTAGE

(1) More than 50 years experience of research and develop in high temperature alloy, corrosion resistance alloy, precision alloy, refractory alloy, rare metal and precious metal material and products.
(2) 6 state key laboratories and calibration center.
(3) Patented technologies.

(4) Ultra-purity smelting process: VIM + IG-ESR + VAR

(5) Excellent high performance.

13 BUSINESS TERM