1.4418 is a martensitic stainless steel with enhanced corrosion resistance and weldability.
Approximate Composition – 16% Cr, 1.0% Mo, 5.0% Ni, 0.04% C (EN composition range. No ASTM equivalent).
This grade combines the following characteristics:
- Best pitting corrosion resistance of all martensitic stainless steel grades approaching that of 304
- Good strength. 700 MPa 0.2%PS, 900 MPa UTS at room temperature
- Excellent toughness, 80 J at room temperature. 40 J at -20°C
- Good weldability, especially for a martensitic stainless steel. No preheating required. Post weld tempering recommended
- Good wet abrasion resistance
This grade is designed to achieve a good balance of corrosion resistant and mechanical properties. The chromium and molybdenum provides corrosion resistance. The low carbon and increased nickel content provides a high strength martensitic structure but with good toughness. There are also significant amounts of austenite and ferrite in the steel. This structure also gives a much improved weldability compared to normal higher carbon martensitic grades. It is proving to be a replacement for grade 431 (1.4057) in some applications.
Applications which illustrate these features include:
Mining, cement plants, hydrofoil legs, anti-seismic applications, helicopter landing grids, penstocks, hydroelectric turbine blades, hardboard and chipboard press plate, propeller shafting, pulp and paper.