Search Results for stainless steel microstructures

This article describes metallographic preparation and examination techniques for stainless steels and maraging steels. It presents a series of micrographs demonstrating microstructural features of these alloys. Procedures used to prepare stainless steels for macroscopic and microscopic examination are similar to those used for carbon, alloy, and tool steels. Cutting and grinding must be carefully executed to minimize deformation because the austenitic grades work harden readily. The high-hardness martensitic grades that contain substantial undissolved chromium carbide are difficult to polish while fully retaining the carbides. 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. The microstructures of stainless steels can be quite complex. Matrix structures vary according to the type of steel, such as ferritic, austenitic, martensitic, precipitation hardenable, or duplex.

Stainless steels are an important class of engineering alloys used in both wrought and cast form for a wide range of applications and in many environments. This article aids in the selection of stainless steels based on weldability and service integrity. Stainless steels are classified by microstructure and are described as ferritic, martensitic, austenitic, or duplex. The article illustrates compositional ranges of the ferritic, martensitic, austenitic, and duplex alloys in the Schaeffler diagram. It describes the metallurgical aspects of welded stainless steels to be considered for particular engineering applications and service conditions. The article discusses the microstructural evolution of the weld metal and the heat-affected zone, susceptibility to defect formation during welding, mechanical and corrosion properties, and weld process tolerance.