Super Alloy Inconel 690™ (UNS N06690)

Topics Covered

Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
     Machinability
     Forming
     Welding
     Heat Treatment
     Forging
     Hot Working
     Cold Working
     Annealing
     Aging
     Hardening
Applications

Introduction

Super alloys have good creep and oxidation resistance. They are also known as high performance alloys, and can be formed in different shapes. Work hardening, precipitation hardening, and solid-solution hardening are performed for strengthening the super alloys. These alloys have the capcity to function at very high temperatures and severe mechanical stress, and also where high surface stability is required.

Inconel 690™ is a nickel-chromium alloy. It has high resistance to hot gases or oxidizing chemicals due to the presence of high chromium content. The following datasheet gives an overview of Inconel 690™.

Chemical Composition

The chemical composition of Inconel 690™ is outlined in the following table.

Element Content (%)
Chromium, Cr 27-31
Iron, Fe 7-11
Silicon, Si 0.5 max
Manganese, Mn 0.5 max
Copper, Cu 0.5 max
Silicon, Si 0.5 max
Carbon, C 0.05 max
Sulfur, S 0.015 max
Nickel, Ni Remainder

Physical Properties

The physical properties of Inconel 690 ™ are given in the following table.

Properties Metric Imperial
Density 8.19 g/cm³ 0.296 lb/in³
Melting point 1343-1377°C 2450-2510°F

Mechanical Properties

The mechanical properties of Inconel 690™ are displayed in the following table.

Properties Metric Imperial
Poisson's ratio 0.29 0.29
Hardness 85 85

Thermal Properties

The following table shows the thermal properties of Inconel 690™.

Properties Metric Imperial
Thermal conductivity 12.1 W/mK 84 BTU in/hr.ft².°F

Other Designations

Other designations that are equivalent to Inconel 690™ include:

  • ASTM B167
  • DIN 2.4642

Fabrication and Heat Treatment

Machinability

Inconel 690™ can be machined using conventional machining methods which are used for iron-based alloys. Machining operations are performed using commercial coolants. High-speed operations such as grinding, milling or turning, are performed using water-base coolants.

Forming

Inconel 690™ can be formed using all conventional techniques.

Welding

Inconel 690™ is welded using gas-tungsten arc welding, shielded metal-arc welding, gas metal-arc welding, and submerged-arc welding methods.

Heat Treatment

Inconel 690™ does not react to heat treatment.

Forging

Inconel 690™ is forged at 1038 to 1233°C (1900 to 2250°F).

Hot Working

Inconel 690™ is hot worked at 872 to 1205°C (1600 to 2200°F).

Cold Working

Inconel 690™ is cold worked using standard tooling.

Annealing

Inconel 690™ is annealed at 1038°C (1900°F) followed by cooling.

Aging

Inconel 690™ does not react to aging thermal treatment.

Hardening

Inconel 690™ is hardened by cold working.

Applications

Inconel 690™ is used in the following applications:

  • Duct work
  • High temperature burners
  • Furnaces
  • Petrochemical heaters

Comments

  1. Milena Krilic-Andan Milena Krilic-Andan Canada says:

    Could you please let me know what is meaning of the ASME B-167 for Alloy 60 designated as "hot - worked (annealed).
    In your Data sheet for Alloy 690 you outlined the following (see below statement):
    Hot Working
    Alloy 690™ is hot worked at 872 to 1205°C (1600 to 2200°F).
    I am not sure what is going with the bar (I am ordering 2/12" bar) when "hot worked" Please explain to me the following: what is going on with the bar  after  hot rolling  at 872 to 1205°C (1600 to 2200°F).  Please specify what is destiny of the bar after last roll mill.:
    a) is bar left to cool in the air or,
    b) bar is "quenched" to keep dissolve carbides and oxides in the solid matrix.

    Thank you.  Milena Krilic-Andan
    Candu Energy Group

    Mississaga
    ON
    Canada

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of AZoM.com.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit