Across APAC's fast-growing refinery and petrochemical sector, heat exchangers face some of the most corrosive service in the plant.
Hot chlorinated seawater, high chloride concentrations and acidic process streams drive pitting, crevice corrosion and stress corrosion cracking. The result is unplanned downtime, premature tube replacement and avoidable safety risk. The most extreme of these environments ask more of a material than conventional corrosion-resistant grades are designed to deliver.
A step beyond super-duplex
SAF® 2707 HD is Alleima's hyper-duplex stainless steel, developed for exactly these conditions. It extends the safe operating window past conventional super-duplex while keeping the economics of a duplex grade rather than a nickel alloy. Three properties matter most for heat exchanger service:
- Corrosion resistance: a minimum PRE of 48 and a critical pitting temperature of 97.5°C, against 80°C for SAF® 2507. In full-scale chlorinated-seawater trials, SAF® 2707 HD showed no pitting under conditions where SAF® 2507 showed attack.
- High strength: proof strength more than double that of standard austenitic stainless steels, allowing thinner walls, lighter bundles and less welding.
- Broad acid resistance: performance in hot organic and sulphuric acids comparable to high-alloy austenitics and nickel alloys such as Hastelloy C276.
Lower total cost of ownership
For a heat exchanger, material choice is a lifecycle decision. SAF® 2707 HD lowers total cost of ownership through longer service life, less unplanned maintenance in aggressive service, and leaner design as higher strength enables thinner walls and fewer welding consumables. The net effect is nickel-alloy-level performance at a cost structure closer to advanced duplex.
Applications and support
SAF® 2707 HD suits tubular heat exchangers in oil refineries, petrochemical and chemical plants, particularly those cooled by chlorinated seawater or handling acidic chloride media. Alleima supports adoption with qualified welding systems (filler Exaton 27.7.5.L), project-specific test welding for demanding cases, and direct access to materials specialists during selection and design.
As refining capacity expands across APAC and India, the materials in critical heat exchangers increasingly decide uptime and lifecycle cost. SAF® 2707 HD lets engineering and procurement teams design that risk out from the start.
→ Talk to our materials experts about SAF® 2707 HD for your next project.