S31675 (ASTM F1586) is a nitrogen reinforced stainless steel for surgical implants, mainly used for hip and knee joints and fracture fixation devices. Its special use requires the material to be very "pure", which means that the content of non-metallic inclusions such as sulfides, alumina, silicates, and spherical oxides is low. This grade of stainless steel is usually produced using the electroslag remelting (ESR) smelting process. ESR is a super refining process that enables stainless steel to have excellent micro cleaning levels that meet regulatory requirements. It can also meet other special requirements of these ASTM standards for implant materials, such as having fine grain structure.

Specs

ASTM F1586

ISO 5832-9

YY0605.9-2007-part 9

EN 10088-3 09/05 X4CrNiMnMo 21-9-4

2.4772

M30NW

Chemical composition

Grain size

Check the grain size of austenite according to the prescribed method, and the result should not be coarser than level 5.

No extral phase

The material shall exhibit no delta ferrite, chi, or sigma phases when it is examined metallographically at 100× magnification.

Microcleanliness

The microcleanliness of the steel, as determined by Test Methods E45, Method A, except using Plate Ir, on representative billet or bar samples from the heat shall not exceed the following:

Characteristic

• S31675 stainless steel has good corrosion resistance and good mechanical properties.
• Strict raw material selection and smelting process ensure the extremely high quality required for the production of stainless steel for surgical implants.
• Due to its composition and absence of ferrite, the steel is completely non magnetic and exhibits excellent resistance to pitting and crevice corrosion in physiological media (Cr%+3.3Mo%+15N%>32).
• The stabilizing effect of niobium can generate excellent intergranular corrosion resistance.
• The combination of smelting and processing processes ensures that the product can obtain uniform, fine-grained materials with very low inclusion levels. This ensures that the product has excellent fatigue resistance, which is ideal for producing parts that withstand high stress.

Product form

Wire, bar, plate, strip, seamless tube, capillary tube