Inconel 718 Plate

Inconel 718 plate is a high-strength,precipitation-hardenable nickel-chromium superalloy engineered to handle extreme environments involving high stress,high temperatures,and severe corrosion.It retains its mechanical integrity and creep-rupture properties at temperatures up to 1300°F (704°C).

Key Performance Advantages

Excellent Weldability:
Unlike older aluminum/titanium-hardened superalloys,718’s sluggish age-hardening reaction allows it to be welded and annealed without spontaneous cracking during heating or cooling cycles.
High Creep-Rupture Strength:
It is designed to resist deformation and rupture under sustained heavy loads at elevated service temperatures.
Corrosion Resistance:
Offers dynamic protection against severe environments,including sea water,hydrogen sulfide ,carbon dioxide,and aggressive organic/industrial acids.

Applications of Inconel 718 Plate

We offer Inconel 718 plates and sheets in thicknesses of 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 6.0.We offer not only stainless steel plates and sheets but also plates made of Hastelloy,Incoloy,Inconel,Monel,and other alloys.Our products comply with ASTM A240,EN 10204,ISO 9001,PED 2014/68/EU ,CE,and other standards.With over a decade of experience in manufacturing and import/export,we are your best wholesaler in China.

Chemical Composition of Inconel 718 Plate

The chemical composition of Inconel 718 plate is defined by standard specifications like AMS 5596 and ASTM B670.It is a nickel-chromium-based superalloy with significant additions of iron,niobium,and molybdenum.

Ni (+Co)	Cr	Fe	Nb (+ Ta)	Mo	Ti	Al	Co	C	Mn	Si	P	S	B	Cu
50.0 – 55.0	17.0 – 21.0	Balance	4.75 – 5.50	2.80 – 3.30	0.65 – 1.15	0.20 – 0.80	≤ 1.0	≤ 0.08	≤ 0.35	≤ 0.35	≤ 0.015	≤ 0.015	≤ 0.006	≤ 0.30

Key Elemental Roles

Nickel:
Forms the austenitic matrix.Provides excellent corrosion resistance and high-temperature stability.
Chromium:
Offers dynamic protection against high-temperature oxidation and hot corrosion.
Niobium:
The most critical addition.It reacts with nickel to form the gamma-double-prime precipitate phase,which gives the alloy its exceptional high strength and prevents strain-age cracking during welding.
Molybdenum:
Provides solid-solution strengthening to the matrix and improves resistance to localized pitting corrosion.
Aluminum & Titanium:
Form the auxiliary gamma-prime precipitate phase to further increase hardness and mechanical strength.

Inconel 718 Standards & Equivalent Designations

Inconel 718 Alloy
Standard / System	Equivalent Designation	Product Form	ASTM	ASME	SAE AMS
UNS Number	UNS N07718	Plates, Sheets & Strips	ASTM B670	ASME SB670	AMS 5596 / 5597
DIN / German Werkstoff	W.Nr. 2.4668	Bars, Rods, Wires & Shapes	ASTM B637	ASME SB637	AMS 5662 / 5663
EN Chemical Name	NiCr19Nb5Mo3	Seamless Pipes & Tubes	ASTM B983	ASME SB983	AMS 5589 / 5590
JIS	NCF 718	Condenser & Heat Exchanger Tubes	ASTM B163	ASME SB163	–
BS	NA 51	Welded Pipes & Tubes	ASTM B705 / B704	ASME SB705 / SB704	AMS 5581
AFNOR	NC19FeNbMo	Forgings & Flanges / Fittings	ASTM B637	ASME SB637	AMS 5664
Generic Trade Name	Alloy 718, Inconel 718

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Kaysuns is a professional supplier of Inconel 718 Plates.Please feel free to contact me if you have any requirements.

Mechanical Properties of Inconel 718 Plate

The mechanical properties of an Inconel 718 plate change drastically depending on its heat-treatment condition.In the standard solution annealed state,the material is ductile and optimized for fabrication.After undergoing precipitation hardening,its tensile and yield strengths nearly double.

Room-Temperature Mechanical Properties

Property	Solution Annealed	Precipitation Aged
Ultimate Tensile Strength	827 – 965 MPa (120 – 140 ksi)	≥ 1,241 MPa (180 ksi)
0.2% Yield Strength	413 – 550 MPa (60 – 80 ksi)	≥ 1,034 MPa (150 ksi)
Elongation (in 2″ or 50mm)	~40% – 50%	≥ 12%
Hardness	≤ 100 HRB (20 – 25 HRC)	≥ 36 HRC (331 HB)

Elastic & Physical Design Constants

Modulus of Elasticity:
29.0 × 10⁶ psi (200GPa) at room temperature.
Poisson’s Ratio:
0.294
Density:
0.296 lb/in³ (8.19 g/cm³)

High-temperature Mechanical Trends

Inconel 718 is heavily favored because it retains high mechanical performance even as operating conditions approach extreme thresholds:

At 1200°F (649°C):The ages plate retains excellent strength,exhibiting a minimum yield strength of ~115 ksi (793 MPa) and an ultimate tensile strength of ~140 ksi (965 MPa).
Creep-rupture Performance (1300 °F / 704°C):Under a sustained high stress of 72.5 ksi (500MPa),a properly ages plate must endure a minimum of 23 hours before rupture according to AMS 5596 requirements.
Cryogenic Toughness:Unlike common carbon steels that become brittle,Inconel 718 plates retain remarkable impact toughness and ductility at sub-zero and cryogenic temperatures down to -320°F (-196°C).

Our Advantages in Manufacturing Inconel 718 Plate

As a professional manufacturer of stainless steel pipes and pipe fittings in China,Kaysuns enhances the microstructural stability of our Inconel 718 plates through heat treatment.Our products offer excellent high-temperature strength,superior structural weldability,and resistance to harsh environments.

High-temperature Strength

The manufacturing process locks in a unique microstructure that retains high tensile,yield,and creep-rupture strength up to 1300°F (704°C).Unlike common alloys that soften,these plates resist thermal deformation under severe,continuous stress.

Microstructural Stability via Heat Treatment

Precision heat treatment alters the internal grain structure of the alloy.Controlled solution annealing and precipitation hardening ensure uniform distribution of the strengthening phases.This eliminates internal voids and eliminates localized material weak points.

Excellent Structural Weldability

The sluggish precipitation-hardening reaction prevents spontaneous strain-age cracking during heating and cooling cycles.Plates can be welded in the annealed state and subsequently aged,allowing for complex fabrications without sacrificing joint integrity.

Severe Environment Resistance

The balanced nickel,chromium,and molybdenum chemistry creates a self-passivating surface layer.The plate blocks aggressive oxidation at high temperatures and prevents localized pitting,crevice corrosion,and sulfide stress cracking in sour oilfield or chemical environments.

FAQs About Inconel 718 Plate

Why is Inconel 718 preferred for welding over other superalloys?

Most nickel-based superalloys are highly susceptible to “strain-age cracking” during post-weld heating.Inconel 718 overcomes this because it is structurally strengthened by niobium rather than aluminum or titanium.Niobium yields a sluggish precipitation response,allowing the material to be welded and cooled without experiencing spontaneous cracking.

Can Inconel 718 plates be used in cryogenic environments?

Yes.Unlike standard structural steels which turn brittle at freezing thresholds,Inconel 718 delivers outstanding cryogenic performance down to -423°F (-253°C).It maintains superb fracture toughness,high ductility,and tensile elasticity,making it ideal for rocket propellant tanks and LNG storage units.

What standard heat treatments apply to Inconel 718 plates?

Solution Annealing:
Heating between 1700°F and 1850°F (925°C to 1010°C) followed by rapid cooling to dissolve secondary phases and optimize ductility.
Precipitation Hardening (Age Hardening):
A two-step process heating to 1325°F (720°C) for 8 hours, furnace cooling to 1150°F (620°C), holding for 8 hours, and air cooling. This process raises final hardness up to 36–45 HRC.

What is the difference between Inconel 718 and Inconel 625 plates?

Inconel 718 Plates:
A precipitation-hardened alloy designed for maximum mechanical strength and creep resistance under load up to 1300°F.
Inconel 625 Plates:
A solid-solution strengthened alloy designed primarily for maximum corrosion resistance, especially against pitting and crevice corrosion in marine or highly acidic settings. It cannot match the mechanical strength of aged 718.

Inconel 718 Plate