This chapter discusses the factors influencing the corrosion resistance of bulk materials, namely alloying, metallurgical factors, and mechanical treatments.

This chapter addresses the general effects of composition, mechanical treatment, surface treatment, processing, and fabrication operations on the corrosion resistance of aluminum and its alloys. Different types of surface treatments covered include claddings, anodizing, and conversion coatings. The processing steps that can have relatively significant impact on corrosion resistance are homogenization, rolling, extrusion, quenching, aging, and annealing.

This chapter discusses the effects of metallurgical factors on the corrosion resistance of magnesium alloys. The factors are chemical composition, heat treating, grain size, and cold-work effects. The chapter describes the causes of corrosion failures in magnesium alloys, namely heavy-metal contamination, blast residues, flux inclusions, and galvanic attack.

Stainless steels and nickel-base alloys are recognized for their resistance to general corrosion and other categories of corrosion. This chapter examines the effects of specific alloying elements, metallurgical structure, and mechanical conditioning on the corrosion resistance of these alloys. Some categories of corrosion covered are pitting, crevice, intergranular, stress-corrosion cracking, general, and high-temperature corrosion.

Titanium and its alloys are used chiefly for their high strength-to-weight ratio, but they also have excellent corrosion resistance, better even than stainless steels. Titanium, as the chapter explains, is protected by a tenacious oxide film that forms rapidly on exposed surfaces. The chapter discusses the factors that influence the growth and quality of this naturally passivating film, particularly the role of oxidizing and inhibiting species, temperature, and alloying elements. It also discusses the effect of different corrosion processes and environments as well as hydrogen, stress-corrosion cracking, liquid metal embrittlement, and surface treatments.

This chapter discusses the sintering process for stainless steel powders and its influence on corrosion resistance. It begins with a review of sintering furnaces and atmospheres and the effect of temperature and density on compact properties such as conductivity, ductility, and strength. It then describes the relationship between sintered density and corrosion resistance and how it varies for different types of powders and operating environments. The chapter also explains how stainless steel powders respond to different sintering atmospheres, including hydrogen, hydrogen-nitrogen, and vacuum, and liquid-phase sintering processes.