This article discusses the role of alloying in the production and use of common refractory metals, including molybdenum, tungsten, niobium, tantalum, and rhenium. It provides an overview of each metal and its alloys, describing the compositions, properties, and processing characteristics as well as the effect of alloying elements. It also discusses strengthening mechanisms and, where appropriate, corrosion behavior.

The refractory metals include niobium, tantalum, molybdenum, tungsten, and rhenium. These metals are considered refractory because of their high melting points, high-temperature mechanical stability, and resistance to softening at elevated temperatures. This article discusses the composition, properties, fabrication procedures, advantages and disadvantages, and applications of these refractory metals and their alloys. A comparison of some of the properties of the refractory metals with those of iron, copper, and aluminum is given in a table. The article concludes with a brief section on refractory metal protective coatings.

This appendix contains recipes of the electrolytic solutions in which various metals are polished in preparation for metallographic examination.

This article discusses the weldability and fusion weld properties of refractory metal alloys. The alloys discussed include tantalum, niobium, rhenium, molybdenum, and tungsten.

Arc welding applies to a large and diversified group of welding processes that use an electric arc as the source of heat to melt and join metals. This chapter provides a detailed overview of specific arc welding methods: shielded metal arc welding, flux cored arc welding, submerged arc welding, gas metal arc welding, gas tungsten arc welding, plasma arc welding, plasma-GMAW welding, electroslag welding, and electrogas welding. The basic characteristics of gases used for shielding during arc welding are briefly discussed.

This appendix is a collection of tables listing coefficients of linear thermal expansion for carbon and low-alloy steels, presenting a summary of thermal expansion, thermal conductivity, and heat capacity; and listing thermal conductivities and specific heats of carbon and low-alloy steels.