Seamless Nickel Alloy Pipe Uns N08800 Alloy 800 High Oxidizing Resistance

Standard Specification for Nickel-Iron-Chromium Alloy Seamless Pipe and Tube

ASTM B407 - 01 

1. Scope

1.1 This specification covers UNS N08120, UNS N08800, UNS N08801, UNS N08810, UNS N08811, and UNS N08890 in the form of cold-worked and hot-finished annealed seamless pipe and tube. Alloy UNS N08800 is normally employed in service temperatures up to and including 1100°F (593°C). Alloys UNS N08120, UNS N08810, UNS N08811, and UNS N08890 are normally employed in service temperatures above 1100°F (593°C) where resistance to creep and rupture is required, and they are annealed to develop controlled grain size for optimum properties in this temperature range.

Introduction

INCOLOY alloys belong to the category of super austenitic stainless steels. These alloys have nickel-chromium-iron as the base metals, with additives such as molybdenum, copper, nitrogen and silicon. These alloys are known for their excellent strength at elevated temperatures and good corrosion resistance in a variety of corrosive environments.

INCOLOY alloy 800 is an alloy of nickel, iron and chromium. The alloy is capable of remaining stable and maintaining its austenitic structure even after long time exposures to high temperatures. Other characteristics of the alloy are good strength, and high resistance to oxidizing, reducing and aqueous environments. The standard forms in which this alloy is available are round, flats, forging stock, tube, plate, sheet, wire and strip.

This datasheet will look into the chemical composition, properties and applications of INCOLOY 800.

Chemical Composition

The chemical composition of INCOLOY alloy 800 is given in the following table.

Physical Properties

The following table discusses the physical properties of INCOLOY alloy 800.

Mechanical Properties

The mechanical properties of INCOLOY alloy 800 are tabulated below.

Other Designations

Some of the designations used to denote INCOLOY alloy 800 are listed below:

Fabrication

Machining characteristics of this INCOLOY alloy 800 are similar to that of iron-based alloys. This alloy tends to work-harden during machining.

Welding

INCOLOY alloy 800 can be welded by common welding techniques, using a matching filler metal.

Forming

This alloy exhibits good ductility and hence can be formed using conventional methods.

Hot working

INCOLOY alloy 800 can be hot worked at temperature ranges of 871-1232°C (1600-2250°F).

Cold Working

Cold working may be done on the alloy using standard tooling.

Annealing

INCOLOY alloy 800 may be annealed after cold working. Annealing should be done at 982°C (1800°F) for 15 min and then the alloy should be air cooled.

Applications

INCOLOY alloy 800 is used in the following applications:

• Heat exchangers
• Carburising equipment
• Heating elements
• Sheathing and nuclear steam generator tubing.