This article addresses electrochemical methods for instantaneous rate determination and threshold determination as well as nonelectrochemical methods that can determine incremental or cumulative rates of corrosion. Electrochemical methods for the study of galvanic corrosion rates and localized corrosion and evaluation of corrosion rates under paints are also discussed. The article describes nonelectrochemical methods that can determine incremental or cumulative rates of corrosion. Methods presented include polarization methods, polarization resistance methods, electrochemical impedance methods, frequency modulation methods, electrochemical noise resistance, potential probe methods, cyclic potentiodynamic polarization methods, potentiostatic and galvanostatic methods, electrochemical noise (EN) methods, scratch-repassivation method, and electrochemical impedance spectroscopy (EIS) techniques. Gravimetric determination of mass loss, electrical-resistance methods, magnetic methods, quartz crystal microbalance method, solution analysis methods, and metrological methods are nonelectrochemical methods. The article presents an electrochemical test that examines the susceptibility of stainless steel alloys to intergranular corrosion.

This article describes the test techniques that are available for monitoring crack initiation and crack growth and for obtaining information on fatigue damage in test specimens. These techniques include optical methods, the compliance method, electric potential measurement, and gel electrode imaging methods. The article discusses the magnetic techniques that are primarily used as inspection techniques for detecting fatigue cracks in structural components. It details the principles and operation procedures of the liquid penetrant methods, positron annihilation techniques, acoustic emission techniques, ultrasonic methods, eddy current techniques, infrared techniques, exoelectron methods, and gamma radiography. The article explains the microscopy methods used to determine fatigue crack initiation and propagation. These include electron microscopy, scanning tunneling microscopy, atomic force microscopy, and scanning acoustic microscopy. The article also reviews the X-ray diffraction technique used for determining the compositional changes, strain changes, and residual stress evaluation during the fatigue process.

Magnetically soft materials are characterized by their low coercivity, an essential requirement for irons and steels selected for any application involving electromagnetic induction cycling. This article provides information on ferromagnetic material properties and how they are affected by impurities, alloying additions, heat treatment, residual stress, and grain size. It also describes classification and testing methods for magnetically soft materials such as high-purity iron, low-carbon steels, silicon steels, iron-aluminum alloys, nickel-iron alloys, iron-cobalt alloys, ferrites, and stainless steels. The article also addresses corrosion resistance and provides insights on the selection of alloys for power generation applications, including motors, generators, and transformers. A short note on the design and fabrication of magnetic cores is also included.