Product focus - INCOLOY® alloy 27-7MO

This super-austenitic stainless steel offers a molybdenum content of around 7.2%, alongside high levels of chromium and nickel, which work together to give the alloy its trademark characteristics. It has better corrosion resistance over similar alloys that have a lower molybdenum content. Molybdenum also contributes a high strength to this alloy, which is a necessary quality for many industrial uses.

One of the key benefits of INCOLOY alloy 27-7MO, is that it can be used as a viable alternative to more expensive alloys in some industries, helping designers and engineers to keep costs down without sacrificing product quality.

Corrosion resistance

It’s most often selected for use in volatile environments, thanks to its ability to withstand many forms of corrosive media at a wide range of temperatures. The inclusion of nickel and nitrogen results in good resistance to stress corrosion cracking and caustic media. It also exhibits excellent resistance to pitting and crevice corrosion. Its Pitting Resistance Equivalency Number (PREN), a means of comparing the corrosion resistance of different alloys, shows that it exceeds similar alloys that contain less molybdenum, and is comparable to some more expensive alloys.
Nickel-chromium alloys containing molybdenum are known for high corrosion resistance in seawater and brine, and as such INCOLOY alloy 27-7MO is often used within marine environments. The higher molybdenum content also gives it resistance to reducing acids, while the inclusion of chromium gives it resistance to oxidising acids. It continues to offer good performance in mixed acid situations, thanks to its compositional makeup.

It is the carefully balanced combination of elements that makes it a good potential choice in many different industries and for myriad uses. Some of its many possible applications include feedwater and process fluid circuits in power plants and in pulp and paper mills, heat exchangers in marine and oil field extraction service, in chemical processing plants, and for wet scrubbing systems for air pollution control.

Working with the alloy

INCOLOY alloy 27-7MO is also a popular choice in many environments due to the ease in which it can be worked. It is readily fabricated and formed through conventional equipment, techniques and products, and it can be both hot and cold formed. It is easily joined with welding processes such as gas tungsten-arc (GTAW), gas metal-arc (GMAW), shielded metal-arc (SMAW), submerged arc (SAW) and plasma arc (PAW). For versatility, the alloy comes in all standard product forms including plate, sheet, rod, bar, wire rod, pipe, tube and forging stock, which makes it useful in a wide variety of situations.

To find out more, visit the INCOLOY alloy 27-7MO product page on our website. If you want to speak to a member of our Sales team, then please Contact Us.