Comparison of Inconel 600 alloy fittings and Inconel 625 fittings

Due to their higher chromium and molybdenum content, Inconel 625 fittings offer superior strength and corrosion resistance compared to Inconel 600 fittings. Inconel 600 fittings, however, are more cost-effective and suitable for high-temperature applications such as heat exchangers. Inconel 625 fittings offer better overall corrosion and oxidation resistance, higher temperature limits (up to 1800°F) in some applications, and greater strength. However, their higher molybdenum and chromium content makes them more expensive and more difficult to process. Inconel 600 fittings have a higher nickel content and are less expensive, making them a good choice when their specific properties meet application requirements.

What is Inconel 600 material?

Inconel 600 is a nickel-chromium alloy with excellent high-temperature oxidation resistance and good corrosion resistance in carburizing and chloride-containing environments. Inconel 600 is a nickel-chromium alloy designed for use in environments ranging from low to high temperatures (up to 2000°F/1093°C).

Nickel 600 Fittings

Key Features: Excellent oxidation resistance, corrosion resistance, and high-temperature resistance.

Typical Applications: Chemical processing, nuclear reactors, heat treatment, and food and fatty acid processing.

Advantages: Excellent performance at high temperatures, and lower cost than Inconel 625.

Considerations: In some environments, its corrosion resistance is not as good as Inconel 625.

Inconel 625 Alloy Fittings

Key Features: Excellent corrosion resistance (including resistance to pitting and crevice corrosion), high strength, and good weldability.

Typical Applications: Marine environments, aerospace, chemical processing, and high-pressure systems.

Advantages: Versatile application, performing well over a wide temperature range from low temperatures to 1800°F (982°C).

Considerations: Higher price than Inconel 600.

Standard Specification For Alloy 600/625 Pipe Fitting

Specifications : ASTM B366 / ASME SB366

Dimensions : ASME/ANSI B16.9, ASME B16.28, MSS-SP-43

Size : Seamless Butt Weld Fittings: 1/2" - 10", Welded Butt Weld Fittings: 1/2" - 48"

Type : Seamless / Welded / Fabricated

Schedule : Sch 5 TO Sch XXS.

Thickness : 20 Swg., 18 Swg., 16 Swg., 14 Swg., 12 Swg., 10 Swg., & Sch. 10, Sch. 40, Sch. 80 etc.

Grades : Inconel 600, 601, 625, 718, 783, 690, x750 Pipe Fittings

Inconel 600 / 625 Pipe Fitting Equivalent Grades

STANDARD	WERKSTOFF NR.	UNS	JIS	BS	GOST	AFNOR	EN
Inconel 600	2.4816	N06600	NCF 600	NA 13	МНЖМц 28-2,5-1,5	NC15FE11M	NiCr15Fe
Inconel 625	2.4856	N06625	NCF 625	NA 21	ХН75МБТЮ	NC22DNB4M	NiCr22Mo9Nb

Chemical Composition of Inconel 600 / 625 Pipe Fittings

Grade	C	Mn	Si	S	Cu	Fe	Ni	Cr
Alloy 600	0.15 max	1.00 max	0.50 max	0.015max	0.50 max	6.00 – 10.00	72.00 min	14.00 – 17.00
Alloy 601	0.10 max	1.0 max	0.5 max	0.015 max	1.0 max	Balance	58.0 – 63.0	21.0 – 25.0
Alloy 625	0.10 max	0.50 max	0.50 max	0.015 max	-	5.0 max	58.0 min	20.0 - 23.0
Alloy 718	0.08 max	0.35 max	0.35 max	0.015 max	0.30 max	-	50.00 - 55.00	17.00 - 21.00

Mechanical Properties of Inconel 600 / 625 Buttweld Fitting

Element	Density	Melting Point	Tensile Strength	Yield Strength (0.2%Offset)	Elongation
Alloy 600	8.47 g/cm3	1413 °C (2580 °F)	Psi – 95,000 , MPa – 655	Psi – 45,000 , MPa – 310	40 %
Alloy 601	8.1 g/cm3	1411 °C (2571 °F)	Psi – 80,000 , MPa – 550	Psi – 30,000 , MPa – 205	30 %
Alloy 625	8.4 g/cm3	1350 °C (2460 °F)	Psi – 1,35,000 , MPa – 930	Psi – 75,000 , MPa – 517	42.5 %
Alloy 718	8.2 g/cm3	1350 °C (2460 °F)	Psi – 1,35,000 , MPa – 930	Psi – 75,000 , MPa – 482	45 %