Difference between Inconel 600 and 718 nickel alloy round bars

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Inconel 600 round bars are a solid solution strengthened alloy with high-temperature resistance (suitable for furnaces and kilns), while Inconel 718 alloy bars are a precipitation hardening alloy known for its excellent strength and toughness at temperatures up to 1300°F (650°C). Its high yield strength, tensile strength, and creep resistance make it ideal for the aerospace and oil/gas industries. The 718 forged bars offer higher strength and are better suited for load-bearing components, while the 600 bars offer good oxidation resistance in less demanding high-temperature environments.

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What is the melting point of Inconel 718?

The melting point range of Inconel 718 is approximately 1260°C to 1336°C (2300°F to 2437°F). Its solidus temperature (the point at which it begins to melt) is 1260°C (2300°F), and its liquidus temperature (the point at which it completely melts) is 1336°C (2437°F). Therefore, it is a high-temperature superalloy suitable for demanding applications in aerospace and industrial fields, such as gas turbines and nuclear reactors.

Inconel 600 bars are high-performance nickel-chromium-iron alloy bars with excellent high-temperature oxidation resistance (up to approximately 1150°C), superior resistance to chloride stress corrosion cracking, and good machinability. They are primarily used in the manufacture and processing of shafts, valve parts, furnace components, and corrosion-resistant structural parts that need to operate in extreme high-temperature and corrosive environments. They are a core raw material for high-reliability critical components in the chemical, nuclear power, heat treatment, and aerospace industries.

Inconel 718 bars are precipitation-hardening nickel-chromium-based superalloys (Inconel 718). Their core characteristic is precipitation strengthening through elements such as niobium and molybdenum, maintaining ultra-high strength and excellent creep and fatigue resistance even at temperatures up to approximately 700°C. They are mainly used in the manufacture of critical structural components subjected to extreme stress and high temperatures, such as aero-engine turbine shafts, high-strength fasteners, oil drilling tools, racing car transmission components, and high-performance molds. They are a top-tier raw material for aerospace, energy, and high-end manufacturing fields with stringent requirements for material mechanical properties and high-temperature stability.

ASTM Specifications

ASTM Specification for Inconel 600

Pipe Smls	Pipe Welded	Tube Smls	Tube Welded	Sheet/Plate	Bar	Forging	Fitting	Wire
B167	B517	B163	B516	B168	B166	B564	B366

ASTM Specification for Inconel 718

Sheet/Plate	Bar	Wire
B670	B637	-

Chemical Composition Comparison: Inconel 600 Bar vs Inconel 718 Bar

Element	Inconel 600 Bar (ASTM B166)	Inconel 718 Bar (ASTM B637)
Nickel (Ni)	≥ 72.0 %	50.0 - 55.0 %
Chromium (Cr)	14.0 - 17.0 %	17.0 - 21.0 %
Iron (Fe)	6.0 - 10.0 %	Balance (~18%)
Niobium (Nb) + Tantalum (Ta)	–	4.75 - 5.50 %
Molybdenum (Mo)	–	2.80 - 3.30 %
Titanium (Ti)	–	0.65 - 1.15 %
Aluminum (Al)	–	0.20 - 0.80 %
Cobalt (Co)	–	≤ 1.00 %
Copper (Cu)	≤ 0.50 %	≤ 0.30 %
Manganese (Mn)	≤ 1.00 %	≤ 0.35 %
Silicon (Si)	≤ 0.50 %	≤ 0.35 %
Carbon (C)	≤ 0.15 %	≤ 0.08 %
Phosphorus (P)	≤ 0.015 %	≤ 0.015 %
Sulfur (S)	≤ 0.015 %	≤ 0.015 %
Boron (B)	–	≤ 0.006 %

Mechanical Properties Comparison: Inconel 600 Bar vs. Inconel 718 Bar

Property	Inconel 600 Bar (Annealed Condition)	Inconel 718 Bar (Solution Annealed & Aged Condition)
Tensile Strength	550 - 655 MPa (80,000 - 95,000 psi)	1240 - 1380 MPa (180,000 - 200,000 psi)
Yield Strength (0.2% Offset)	240 - 415 MPa (35,000 - 60,000 psi)	1035 - 1170 MPa (150,000 - 170,000 psi)
Elongation (in 2 in. or 50 mm)	40 - 55 %	12 - 20 %
Reduction of Area	50 - 65 %	20 - 35 %
Hardness	150 - 220 HB	330 - 410 HB
Modulus of Elasticity (Young's Modulus)	214 GPa (31.0 × 10⁶ psi)	200 GPa (29.0 × 10⁶ psi)
Fatigue Strength (Rotating Beam, 10⁸ cycles)	~240 MPa (~35,000 psi)	~480 MPa (~70,000 psi)

Differences between Inconel 600 and Inconel 718 Round Bars – Applications

The wide range of applications for Inconel 600 and Inconel 718 bars reflects their unique mechanical and chemical properties. Inconel 600 bars are widely used in the chemical industry, often in applications involving contact with highly corrosive chemicals and corrosive environments. Due to their excellent oxidation resistance and seawater corrosion resistance, Inconel 600 bars are also used in the aerospace and marine industries.

On the other hand, Inconel 718 bars have extensive applications in the aerospace field, particularly in the manufacture of turbine disks, shafts, and other high-temperature components. Their superior high-temperature strength and creep resistance ensure reliable engine performance under extreme temperatures. Inconel 718 bars are also used in the oil and gas industry, where their corrosion resistance and high-temperature strength are crucial for downhole components.

Why Choose Gnee as Your Nickel-Based Alloy Supplier

✅ Over 18 years of export experience, products sold to more than 80 countries

✅ Certified by ISO, SGS, and BV

✅ Global inventory of Inconel, Hastelloy, Incoloy, and Monel alloy tubing, plates, and bars

✅ Custom processing services available – including cutting, polishing, CNC machining, and packaging

✅ Fast delivery within 7-15 days, supported by global logistics partners

📦 Packaging and Shipping

All stainless steel products are packaged using the following methods:

Wooden pallets or crates

Moisture-proof packaging

Labels with furnace number, standard, and size labels

Shipped worldwide by sea, air, or express