Introduction

Inconel 718 is a nickel-chromium-molybdenum alloy  designed to resist a wide range of severely corrosive environments, pitting  and crevice corrosion. This nickel steel alloy also displays exceptionally  high yield, tensile, and creep-rupture properties at high temperatures. This  nickel alloy is used from cryogenic temperatures up to long term service at  1200° F. One of the distinguishing features of Inconel 718’s composition is  the addition of niobium to permit age hardening which allows annealing and  welding without spontaneous hardening during heating and cooling. The  addition of niobium acts with the molybdenum to stiffen the alloy’s matrix  and provide high strength without a strengthening heat treatment. Other  popular nickel-chromium alloys are age hardened through the addition of  aluminum and titanium. This nickel steel alloy is readily fabricated and may  be welded in either the annealed or precipitation (age) hardened condition.  This superalloy is used in a variety of industries such as aerospace,  chemical processing, marine engineering, pollution-control equipment, and  nuclear reactors.

Character

l    Good mechanical properties – tensile, fatigue and  creep-rupture

l    Yield tensile strength, creep, and rupture strength  properties are exceedingly high

l    Highly resistant to chloride and sulfide stress  corrosion cracking

l    Resistant to aqueous corrosion and chloride ion stress  corrosion cracking

l    High temperature resistant

l    Age-hardenable with a unique property of slow aging response  that permits heating and cooling during annealing without the danger of  cracking.

l    Excellent welding characteristics, resistant to  postweld age cracking

Application

l    Chemical processing

l    Aerospace

l    Liquid fuel rocket motor components

l    Pollution-control equipment

l    Nuclear reactors

l    Cryogenic storage tanks

l    Valves, fasteners, springs, mandrels, tubing hangers

l    Well head completion equipment and blow out preventers  (BOP’s)

l    Gas turbine engine parts

Equal grade

Alloy 718, Haynes 718, Nicrofer 5219,  Allvac 718, Altemp 718, GH4169, UNS N07718

Chemical composition  (%)

Nickel (plus Cobalt)  .......................................................50.00-55.00

Chromium......................................................................17.00-21.00

Iron  .....................................................................................Balance*

Niobium (plus  Tantalum)....................................................4.75-5.50

Molybdenum  .....................................................................2.80-3.30

Titanium.............................................................................0.65-1.15

Aluminum ..........................................................................0.20-0.80

Cobalt  ...............................................................................1.00  max.

Carbon..............................................................................0.08  max.

Manganese  .......................................................................0.35  max.

Silicon  ...............................................................................0.35  max.

Phosphorus.....................................................................0.015  max.

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

Boron  ..............................................................................0.006  max.

Copper..............................................................................0.30  max.

Standards

Rod, Bar, Wire  and Forging Stock - ASTM B 637, ASME SB 637, SAE AMS 5662, SAE AMS 5663,  SAE AMS 5664, SAE AMS 5832, SAE AMS 5914, SAE AMS 5962

Plate, Sheet and  Strip - ASTM B 670,  ASTM B 906, ASME SB 670, ASME SB 906, SAE AMS 5596, SAE AMS 5597, SAE AMS  5950

Pipe and Tube - SAE AMS 5589, SAE AMS 5590

Forms available  at A-one Alloy

Plate, sheet, strip, wire, rod, bar,  forging, pipe, tube, fitting, powder

Delivery

Plenty of bars and forging in stock. For  delivery of other products please contact A-one Alloy for confirmation.