This chapter describes how ultrasonic testing came to be a viable method for evaluating intergranular stress-corrosion cracking (SCC) in large-diameter stainless steel pipe welds in boiling water reactor service. Intergranular SCC can be difficult to detect using nondestructive evaluation (NDE) techniques because of its treelike branching pattern and its location in the heat-affected zone within the weld. As the chapter explains, by optimizing excitation and reflected waveforms, switching to dual-element sensing, properly orienting the scanning path, and using crack-tip diffraction and amplitude-drop techniques, the height, length, and location of intergranular cracks can be accurately determined anywhere along the walls of the pipe as well as in weld areas.

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.