Incoloy 27-7MO (Alloy 27-7MO, UNS S31277) Bar/Rod Description:
Inconel®, Incoloy®, Monel® have Registered Trademarks of Special Metals Corporation and its subsidiaries.
Incoloy alloy 27-7MO is an advanced 7% molybdenum super-austenitic stainless steel offering corrosion resistance in most environments superior to 6% molybdenum super-austenitic stainless steels. In many environments, Incoloy 27-7MO (UNS S31277) offers resistance approaching that of much more highly alloyed materials such as INCONEL alloys 625, 22, and C-276.
Incoloy 27-7MO products typically contain 27% nickel, 22% chromium, 7.2% molybdenum, and 0.34% nitrogen. By virtue of its content of molybdenum, chromium, and nitrogen, alloy 27-7MO offers excellent resistance to pitting and crevice corrosion. The nickel, nitrogen, and molybdenum provide resistance to reducing media while a high content of chromium offers resistance to oxidizing media. Incoloy 27-7MO performs well in mixed acid environments, especially those containing oxidizing and reducing acids.
Other trade names: Alloy 27-7MO, UNS S31277

Incoloy 27-7MO (Alloy 27-7MO, UNS S31277) Bar/Rod Specifications:
Metal Type: UNS S31277
Standard: ASTM A 479/ASME SA 479
Chemical Composition, %
|
Ni |
Cr |
Mo |
Mn |
Cu |
Si |
N |
P |
C |
S |
Fe |
Min |
26 |
20.5 |
6.5 |
|
0.5 |
|
0.3 |
|
|
|
Balance |
Max |
28 |
23 |
8 |
3.0 |
1.5 |
0.5 |
0.4 |
0.03 |
0.02 |
0.01 |
Incoloy 27-7MO (Alloy 27-7MO, UNS S31277) Bar/Rod Applications:
As Incoloy 27-7MO offers a unique combination of corrosion resistance, high strength, and ease of fabrication, it is applied in many industries, such as pollution control, power, marine, chemical processing, pulp and paper, oil, gas, etc.
- Chemical Processing:
- Widely used in the chemical industry for its outstanding corrosion resistance in aggressive chemical environments.
- Marine Engineering:
- Applied in marine engineering applications where resistance to seawater and salt spray corrosion is essential.
- Pollution Control Equipment:
- Utilized in the construction of pollution control equipment due to its ability to withstand corrosive gases and chemicals.
- Pulp and Paper Industry:
- Found in components for pulp and paper processing, providing durability in corrosive paper manufacturing environments.
- Oil and Gas Extraction:
- Employed in oil and gas extraction operations where resistance to corrosive elements is critical for equipment longevity.
FAQs
Q1. What is Incoloy 27-7MO Bar/Rod?
Incoloy 27-7MO (UNS S31277) bar/rod is a super-austenitic stainless steel alloy designed for exceptional corrosion resistance and high strength, particularly in environments where resistance to pitting, crevice corrosion, and stress corrosion cracking is required. It is ideal for use in harsh environments such as marine, chemical processing, and pollution control industries.
Q2. What are the key properties of Incoloy 27-7MO Bar/Rod?
- High Corrosion Resistance – Excellent resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC).
- Strength – High strength and toughness in both ambient and elevated temperatures.
- Good Fabricability – Can be easily welded, formed, and machined.
- Resistance to Acids – Performs well in sulfuric, hydrochloric, phosphoric, and nitric acids.
Q3: 3. What are the applications of Incoloy 27-7MO Bar/Rod?
- Marine Engineering – Components exposed to seawater and offshore environments, such as pumps and heat exchangers.
- Chemical Processing – Valves, pumps, and other equipment exposed to aggressive chemicals.
- Pollution Control – Used in scrubbers and filters in industries dealing with sulfur and other harmful compounds.
- Aerospace – Components exposed to corrosive environments at high temperatures.