BÖHLER P558

BÖHLER P558 is a high-nitrogen 11% manganese-17% chromium-3% molybdenum-nickel stainless steel for surgical implants. Its metallurgical requirements include a fine-grained, austenitic microstructure without delta ferrite, low inclusion content, and resistance to intergranular corrosion.

BÖHLER P558 also exhibits pitting and crevice corrosion resistance that is significantly better than the reference material in Specification F138 and exceeds the material values ​​specified in Specification F1314 and Specification F1586. Biocompatibility tests for this material have been positive and meet the requirements of the test standards used.

The chemical composition of this steel features a high carbon content, along with high nitrogen content. The high carbon content is considered critical in the conventional metallurgy of chromium-nickel stainless steels, but the simultaneous alloying of nitrogen and carbon in BÖHLER P558 has a beneficial effect on the stabilization of the austenitic phase, extends the range of austenite stability to lower solution annealing temperatures, increases corrosion resistance, and leads to better toughness properties.