Inconel Alloy 690 Introduction to Characteristics and Execution Standards

Inconel Alloy 690 Introduction to Characteristics and Execution Standards

Common Trade Names: Inconel 690, Alloy 690, Nickel 690.

INCONEL alloy 690 (UNS N06690/W. Nr. 2.4642) is a high-chromium nickel alloy having excellent resistance to many corrosive aqueous media and high- temperature atmospheres. In addition to its corrosion resistance, alloy 690 has high strength, good metallurgical stability, and favorable fabrication characteristics.

The substantial chromium content gives the alloy outstanding resistance to oxidizing chemicals and to high-temperature oxidizing gases. The high level of nickel imparts resistance to stress- corrosion cracking in chloride-containing environments as well as to sodium hydroxide solutions.

The properties of INCONEL alloy 690 are useful for various applications involving nitric or nitric/hydrofluoric acid solutions. Examples are tail-gas reheaters used in nitric acid production and heating coils and tanks for nitric/hydrofluoric solutions used in pickling of stainless steels and reprocessing of nuclear fuels.

The alloy’s resistance to sulfur-containing gases makes it an attractive material for such applications as coal-gasification units, burners and ducts for processing sulfuric acid, furnaces for petrochemical processing, recuperators, incinerators, and glass vitrification equipment for radioactive waste disposal.

In various types of high-temperature water, alloy 690 displays low corrosion rates and excellent resistance to stress-corrosion cracking. Thus, alloy 690 is widely used for steam generator tubes, baffles, tubesheets, and hardware in nuclear power generation.

Available Product Forms: Plate, round bar, forging stock, pipe and tube;

Specifications:Alloy 690 is designated as UNS N06690, W. Nr. 2.4642 and ISO NW6690.

Rod, Bar, Wire and Forging Stock: - ASTM B166; ASME SB 166, ASTM B 564; ASME SB 564, ASME Code Case N-525, ISO 9723, MIL-DTL-24801;

Seamless Pipe and Tube: - ASTM B 163; ASME SB 163, ASTM B 167; ASME SB 167, ASTM B 829; ASME SB 829, ASME Code Cases 2083, N- 20, N-525, ISO 6207, MIL- DTL-24803

Plate, Sheet, and Strip: - ASTM B168; ASME SB 168; ASME N-525, ISO 6208, MIL-DTL-24802;

Welding Products: - INCONEL Filler Metal 52 - AWS A5.14 / ERNiCrFe-7; INCONEL Welding Electrode 152 - AWS A5.11 / ENiCrFe-7;

Inconel Alloy 690Chemical Composition

Limiting Chemical Composition, %  by Weight 

Nickel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58.0 min.

Chromium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.0-31.0;

Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.0-11.0;

Carbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 max.

Silicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.50max.

Manganese . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.50max.

Sulfur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.015 max.

Copper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.50 max.