BÖHLER N324 is a corrosion-resistant steel with 13%Cr ,1,3% Mo and 1,2 % Ni-addition in the form of bars, wire, forgings, and forging stock. The steel is a free machining grade containing around 0,2% Sulfur with a better corrosion resistance and hardness and toughness than steels of standard 13% Cr variants in the hardened & tempered condition.
These products have been used typically for parts in general engineering and for uncritical cutting and non cutting medical applications , e.g. cutters and burrs, needles, scissors, drill bits, screws and even blades requiring hardness up to 48/53 HRC and resistance to wear, corrosion, and oxidation depending on instrument design and application. But usage is not limited to such applications.
High surface finish is required to develop adequate corrosion resistance after quality heat treatment. Polishing and passivation treatment is recommended. Tempering over 427 °C [800 °F] results in reduced corrosion resistance.
It is not recommended that free-machining grades be used for critical portions of surgical instruments. Free machining grades should only be considered for instrument applications when appropriate steps can be taken during manufacture to minimize the inherent limitations of this class of alloys.
| Market grade | SEL | EN |
|---|---|---|
| 420F-Mod | 1.4197 | X20CrNiMoS13-1 |
| ASTM |
|---|
| F899 |
| C | Si | Mn | P | S | Cr | Mo | Ni | |
|---|---|---|---|---|---|---|---|---|
| 0.20 to 0.26 | max. 1.00 | max. 2.00 | max. 0.04 | 0.15 to 0.27 | 12.50 to 14.00 | 1.10 to 1.50 | 0.75 to 1.50 |
