STAINLESS STEELS are complex alloys containing a minimum of 11% Cr plus other elements to produce ferritic, martensitic, austenitic, duplex, or precipitation-hardenable grades. Procedures used to prepare stainless steels for macroscopic and microscopic examination are similar to those used for carbon, alloy, and tool steels. However, certain types require careful attention to prevent artifacts. Because the austenitic grades work harden readily, cutting and grinding must be carefully executed to minimize deformation. The high-hardness martensitic grades that contain substantial undissolved chromium carbide are difficult to polish while fully retaining the carbides. The most difficult to such grades to prepare is AISI 440C. For the most part, preparation of stainless steels is reasonably simple if the basic rules for metallographic preparation arefollowed. However, unlike carbon, alloy, and tool steels, etching techniques are more difficult due to the high corrosion resistance of stainless steels and the various second phases that may be encountered.