Alleima is a leading manufacturer of high value-added products in advanced stainless steels and special alloys. Our origins date back to 1867 and the foundation of the company Sandvikens Jernverk by Göran Fredrik Göransson, a pioneer in using the Bessemer method for steel production on an industrial scale.
Based on long-term customer partnerships, we advance processes and applications in the most demanding industries through unique materials that are lightweight, durable, corrosion-resistant, and able to withstand extremely high temperatures and pressures. Listening to our customers’ material requirements for their businesses, via face-to-face meetings or customer surveys, inspired the development of our new super-austenitic alloy bridging the gap between stainless steel and nickel alloys Sanicro® 35 – bridging the gaps to new opportunities.
Sanicro® 35 bridges the properties gap between super austenitic steel grades and more expensive high nickel alloys. Sanicro® 35 is available in Heat Exchanger Tubes, Hydraulic and Instrumentation Tubing, and regular tube and pipe form. Containing 35% nickel, it provides a high-performance alternative to conventional high nickel alloys and super austenitic alloys to support more cost-effective and efficient operations.
PROPERTIES
The composition of the alloy was very carefully chosen. A number of trials and tests were conducted to arrive at the optimum range of alloying elements. The composition of the alloy is:
This balanced chemistry gives Sanicro® 35 a very high structural stability and a PRE > 52 predicts excellent pitting corrosion resistance
Sanicro® 35 has an excellent yield strength of 425 MPa for heat exchanger & hydraulic & instrumentation tube, but pipe has a 400Mpa and an elongation of a minimum of 35%. This combination allows designers to look for component weight reduction possibilities by reducing the wall thickness of the tube without compromising the pressure rating
CORROSION PROPERTIES
To prove the alloy’s capabilities, particularly its potential for deployment in conditions such as seawater or chloride containing environments,
Sanicro® 35’s corrosion resistance and mechanical properties were tested and compared with other existing stainless steels and nickel-based alloys.
Electrochemical pitting corrosion tests shows Sanicro 35 being superior to the super austenitic 6Mo grade 254 SMO and on par with Alloy 625. This makes the grade a suitable alternative to both these grades when pitting corrosion is a concern.
Sanicro® 35 provided a critical crevice corrosion temperature (CCT) that was significantly higher than alloy 625, In ASTM G48 method D, Sanicro® 35 displayed a CCT of 52.5°C, while in ASTM G48 method F, the CCT was 45°C. In the same test, the CCT values for alloy 625 were 45°C and 25°C, respectively. The CCT values for Sanicro® 35 were similar to those of alloy C-276Based on these tests, it is expected that Sanicro® 35 offers better crevice corrosion resistance than alloy 625 and at least on par with alloy C-276.
Industry benefits
In the hydraulic and instrumentation (H&I) tubing sector, Sanicro® 35 the new material bridges the gap between high alloyed austenitic stainless steel and expensive nickel alloys helping to streamline inventories, reducing the amount of capital tied up in product portfolios, and providing a safe alternative to more expensive materials.
For high-performance heat exchangers (HX), Sanicro® 35 can be used at high temperatures and is a cost-effective alternative to nickel alloys. These benefits can support lower lifecycle costs, eliminate unscheduled downtime, combat general and pitting corrosion, and avoid crevice corrosion. Sanicro® 35 generates confidence in material selection and provides the opportunity to reduce costly over-conservatism. It delivers performance appropriate to the demands of the job. In today’s cost-conscious environment, Sanicro® 35 is an all-round tube solution for many H&I and HX challenges.
The alloy won the materials design category in the Materials Performance Corrosion Innovation of the Year Awards at NACE Corrosion 2021.
Available locally
“Sanicro® 35 is a more robust alloy than other austenitic or super-austenitic steel grades and a great alternative to nickel alloys,” says Helen Harvey – Regional Sales Director UK.
To find out more, contact our local sales office, sales.uk@alleima.com, Tel: 01782 228940 or visit our website for more products and information.
