Zeron 100 (UNS S32760, Wnr. 1.4501), developed by Weir Materials (now part of Rolled Alloys) from research carried out at the University of Manchester, is a proprietary super duplex stainless steel distinguished from other super duplex grades by two deliberate alloy additions: tungsten (0.50-1.00%) and copper (0.50-1.00%). Both are unusual in the duplex family — most super duplex grades rely on chromium, molybdenum, and nitrogen alone. The tungsten addition further strengthens resistance to localized corrosion (pitting and crevice attack) beyond what molybdenum alone delivers, while the copper addition improves resistance to non-oxidizing and mineral acids like sulfuric and hydrochloric acid, an environment where straight Cr-Mo-N duplex alloys are comparatively weak.

Zeron 100 retains the balanced 50/50 austenite-ferrite microstructure common to the duplex family, delivering roughly double the yield strength of standard austenitic stainless along with a PREN (including the tungsten contribution) comfortably above 40. That combination of very high mechanical strength, resistance to a wider range of corrosive media than most duplex grades, and a long offshore performance track record makes Zeron 100 a standard specification for critical oil and gas equipment — subsea manifolds, wellhead components, pump shafts, and valve bodies — as well as marine and desalination hardware operating in aggressive chloride and mixed-acid environments.

Zeron 100 carries the same dual-phase austenite-ferrite machining fundamentals as every duplex grade on this site — higher cutting forces than a standard austenitic stainless from the ferrite phase, moderate work hardening from the austenite phase, and low thermal conductivity that concentrates heat at the tool edge — but the tungsten and copper additions that define this grade add an extra layer of abrasive wear beyond what a straight Cr-Mo-N super duplex like 2507 presents. Tungsten in particular is a dense, hard, carbide-forming element, and its presence in the microstructure increases abrasive tool wear noticeably compared with duplex grades that rely on molybdenum alone for corrosion resistance.

The practical approach mirrors what works on other super duplex grades, just with less margin: a robust, wear-resistant coated insert with strong edge support rather than a fine, aggressive geometry, rigid workholding and machine setup to handle the high cutting forces without deflection, and reduced speeds and feeds relative to standard duplex grades like 2205. Coolant is important both for managing heat at the cutting edge and for controlling built-up edge tendencies on the copper-bearing microstructure. Shops experienced with 2507 or 255 should expect Zeron 100 to behave similarly, with somewhat faster insert wear from the tungsten content as the main practical difference.