Inconel vs Hastelloy

by ASC

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Posted on May 08, 2022 at 10:25 AM

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Inconel and Hastelloy are both nickel-chromium-molybdenum-based alloys. They are all corrosion-resistant and extremely strong metals. Hastelloy has greater molybdenum content than Inconel, although Inconel has a higher chromium concentration. This sets them apart in terms of corrosion resistance in different situations.

What is Hastelloy?

Hastelloy is an alloy of nickel and molybdenum. It is available in a number of grades, many of which are nickel chromium molybdenum alloys. Although each Hastelloy grade was developed for a distinct use, they are all extremely corrosion resistant. At high temperatures, Hastelloy is strengthened and hardened, making it perfect for welding applications. It's easy to shape and build. They can be forged and cold worked because of their ductility. Hastelloy is a suitable choice for high-temperature applications because of its outstanding resistance to strongly oxidizing and reducing chemicals. In the chemical and petrochemical sectors, pipes and valves are widely used. It works well in heat exchangers and pressure vessels, as well as nuclear and chemical reactors.

Forging Inventory of Nickel Alloys

• ALLOY B2
• ALLOY C
• ALLOY C276
• ALLOY N
• ALLOY S
• ALLOY W
• ALLOY X

Hastelloy Chemical Composition

Alloy*	C%	Co%	Cr%	Mo%	V%	W%	Ai%	Cu%	Nb %	Ti%	Fe%	Ni%	Other%
Hastelloy B	0.1	1.25	0.6	28	0.3	-	-	-	-	-	5.5	rest/bal	Mn 0.80; Si 0.70
Hastelloy B2 / Hastelloy B-2	0.02	1	1	26.0-30.0	-	-	-	-	-	-	2	rest/bal	Mn 1.0, Si 0.10
Hastelloy C	0.07	1.25	16	17	0.3	40	-	-	-	-	5.75	rest/bal	Mn 1.0; Si 0.70
Hastelloy C4 / Hastelloy C-4	0.015	2	14.0-18.0	14.0-17.0	-	-	-	-	-	0..70	3	rest/bal	Mn 1.0 ; Si 0.08
Hastelloy C276 / Hastelloy C-276	0.02	2.5	14.0-16.5	15.0-17.0	0.35	3.0-4.5	-	-	-	-	4.0-7.0	rest/bal	Mn 1.0; Si 0.05
Hastelloy F	0.02	1.25	22	6.5	-	0.5	-	-	2.1	-	21	rest/bal	Mn 1.50; Si 0.50
Hastelloy G	0.05	2.5	21.0-23.5	5.5-7.5	-	1	-	1.5-2.5	1.7-2.5	-	18.0-21.0	rest/bal	Mn 1.0-2.0; P0.04; Si 1.0;
Hastelloy G2 / Hastelloy G-2	0.03	-	23.0-26.0	5.0-7.0	-	-	-	0.70-1.20	-	0.70-1.50	rest/bal	47.0-52.0	Mn 1.0; Si 1.0
Hastelloy N	0.06	0.25	7	16.5	-	0.2	-	0.1	-	-	3	rest/bal	Mn 0.40; Si 0.25; B 0.01
Hastelloy S	0.02	2	15.5	14.5	0.6	1	0.2	-	-	-	3	rest/bal	Mn 0.50; Si 0.40; B0.0009; La 0.02
Hastelloy W	0.06	1.25	5	24.5	-	-	-	-	-	-	5.5	rest/bal	Mn 0.050; Si 0.50
Hastelloy X	0.1	1.5	22	9	-	0.6	-	-	-	18.5	-	rest/bal	Mn 0.6; Si 0.60

Hastelloy Melting Point, Density and Tensile Strength

	Density	Melting Point	Tensile Strength	Yield Strength (0.2%Offset)	Elongation
C22	8.69 g/cm3	1399 °C (2550 °F)	Psi – 1,00,000 , MPa – 690	Psi – 45000 , MPa – 310	45 %
C276	8.89 g/cm33	1370 °C (2500 °F)	Psi – 1,15,000 , MPa – 790	Psi – 52,000 , MPa – 355	40%
B2	9.2 g/cm3	1370 °C (2550 °F)	Psi – 1,15,000 , MPa –760	Psi – 52,000 , MPa – 350	40%
B3	9.2 g/cm3	1370 °C (2550 °F)	Psi – 1,15,000 , MPa –760	Psi – 52,000 , MPa – 350	40%
C4	8.64 g/cm3	1350-1400 °C	783	365	55%
Hybrid BC1	8.83 g/cm³	1343 - 1443°C	725	310	40%
X	8.22 g/cm³	1355°C	655 MPa	240 MPa	35%

Hastelloy Equivalent Grades

STANDARD	WERKSTOFF NR.	UNS	GOST	AFNOR	JIS	OR	EN
Hastelloy C22	2.4602	N06022	-	-	NW 6022	-	NiCr21Mo14W
Hastelloy C276	2.4819	N10276	ХН65МВУ	-	NW 0276	ЭП760	NiMo16Cr15W
Hastelloy B2	2.4617	N10665
Hastelloy B3	2.4600	N10675
Hastelloy C4	2.4610	N06455
Hastelloy C-22HS	-	N07022
Hastelloy C2000	2.4675	N06200
Hastelloy Hybrid BC1	2.4708	N10362
Hastelloy X	2.4665	N06002

What is Inconel?

Inconel is a corrosion-resistant and oxidation-resistant alloy that is ideally suited for high-temperature and high-pressure purposes. When Inconel alloy is treated, a thick, persistent oxide layer forms, protecting the surface from further damage. The strength of Inconel varies with temperature. It produces high temperature strength by solid solution strengthening or precipitation hardening, depending on the alloy. Inconel is a metal used extensively for high-temperature purposes.

Read More about -  What is Inconel and Why to Use it?

Inconel Material Specification

• Inconel 600
• Inconel 601
• Inconel 625
• Inconel 718
• Inconel X750
• Inconel 690

Inconel Chemical Composition

Inconel	Element (% by mass)
	Ni	Cr	Fe	Mo	Nb	Co	Mn	Cu	Al	Ti	Si	C	S	P	B
600	72.0	14.0–17.0	6.0–10.0				1.0	0.5			0.5	0.15	0.015
617	44.2–56.0	20.0–24.0	3.0	8.0–10.0		10.0–15.0	0.5	0.5	0.8–1.5	0.6	0.5	0.15	0.015	0.015	0.006
625	58.0	20.0–23.0	5.0	8.0–10.0	3.15–4.15	1.0	0.5		0.4	0.4	0.5	0.1	0.015	0.015
690	59.5	30	9.2				0.35	0.01	0.02		0.35	0.019	0.003
718	50.0–55.0	17.0–21.0	balance	2.8–3.3	4.75–5.5	1.0	0.35	0.2–0.8	0.65–1.15	0.3	0.35	0.08	0.015	0.015	0.006
X-750	70.0	14.0–17.0	5.0–9.0		0.7–1.2	1.0	1.0	0.5	0.4–1.0	2.25–2.75	0.5	0.08	0.01

Inconel Melting Point, Density and Tensile Strength

	Density	Melting Point	Tensile Strength	Yield Strength (0.2%Offset)	Elongation
600	8.47 g/cm3	1413 °C (2580 °F)	Psi – 95,000 , MPa – 655	Psi – 45,000 , MPa – 310	40 %
601	8.1 g/cm3	1411 °C (2571 °F)	Psi – 80,000 , MPa – 550	Psi – 30,000 , MPa – 205	30 %
617	8.3g/cm³	1363°C	≥ 485 MPa	≥ 275 MPa	25 %
625	8.4 g/cm3	1350 °C (2460 °F)	Psi – 135,000 , MPa – 930	Psi – 75,000 , MPa – 517	42.5 %
690	8.3g/cm³	1363°C	≥ 485 MPa	≥ 275 MPa	25 %
718	8.2 g/cm3	1350 °C (2460 °F)	Psi – 135,000 , MPa – 930	Psi – 70,000 , MPa – 482	45 %
725	8.31 g/cm3	1271°C-1343 °C	1137 MPa	827 MPa	20 %
X-750	8.28 g/cm3	1430°C	1267 MPa	868 MPa	25 %

Inconel Equivalent Grades

STANDARD	WERKSTOFF NR.	UNS	GOST	AFNOR	JIS	BS	EN	OR
Inconel 600	2.4816	N06600	МНЖМц 28-2,5-1,5	NC15FE11M	NCF 600	NA 13	NiCr15Fe	ЭИ868
Inconel 601	2.4851	N06601	XH60BT	NC23FeA	NCF 601	NA 49	NiCr23Fe	ЭИ868
Inconel 617	2.4663	N06617
Inconel 625	2.4856	N06625	ХН75МБТЮ	NC22DNB4M	NCF 625	NA 21	NiCr22Mo9Nb	ЭИ602
Inconel 690	2.4642	N06690
Inconel 718	2.4668	N07718
Inconel 725	-	N07725
Inconel X-750	2.4669	N07750

Mechanical Behavior

Inconel and Hastelloy are both solid solution reinforced alloys with equivalent mechanical properties. It's just that they use a lot of different solid solution strengthening components.

Application

As shown, both alloys have a wide variety of functions. And, to a large extent, their applicability range is extremely close. This does not, however, mean that the two alloys can be used alternately. According to the application environment, various alloys should be employed in the same application.
In oil and gas applications, for example, the subsurface environment of various oil fields varies greatly. Inconel is a superior choice when oil fields are subjected to an oxidising environment. In oil fields with declining conditions, Hastelloy should be used.
Hastelloy will cost a little extra because molybdenum is more costly than chromium. Their prices, on the other hand, are not vastly different.

Conclusion

Corrosion resistance is strong in both Inconel and Hastelloy. For oxidising environments, Inconel is a better choice. Hastelloy C-276 is preferable for decreasing conditions.

Both alloys are strengthened by solid solution. Despite the fact that the components that have a solid solution strengthening effect are different, the mechanical characteristics of the two are very similar.The two alloys have similar application ranges; however they serve distinct functions in the same application.

Amardeep Steel Centre holds the expertises in manufacturing & fabricating Inconel and Hastelloy products to your specifications and needs. Please contact our experts if you have any purchasing requirements.

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