This article describes some of the general characteristics associated with the corrosion of weldments. The role of macrocompositional and microcompositional variations, a feature common to weldments, is emphasized in this article to bring out differences that need to be realized in comparing corrosion of weldments to that of wrought materials. The article discusses the most important methods available to minimize corrosion in weldments.

This chapter discusses the use of finite-element methods for modeling cold forging processes. The discussion covers process modeling inputs, such as geometric parameters, material properties, and interface conditions, and includes several application examples.

This chapter describes an investigation following an aircraft accident in which the main undercarriage struts had failed. Visual examination revealed that the starboard strut fractured about 13 cm from the end nearest the underside of the wing. A close-up view of the fracture surface indicated that cracking initiated at the outer periphery of the strut and propagated inward until overload fracture occurred. SEM imaging revealed fatigue striations along the outer periphery and dimples elsewhere, indicative of tensile overload. Based on these observations, investigators concluded that the starboard strut failed by fatigue, which overloaded the port side strut as evidenced by its slant type fracture pattern.

This chapter describes the mechanical properties of fully pearlitic microstructures and their suitability for wire and rail applications. It begins by describing the ever-increasing demands placed on rail steels and the manufacturing methods that have been developed in response. It then explains how wire drawing, patenting, and the Stelmor process affect microstructure, and describes various fracture mechanisms and how they appear on steel wire fracture surfaces. The chapter concludes by discussing the effects of torsional deformation, delamination, galvanizing, and aging on patented and drawn wires.

Two compressor rotors of similar design and construction were severely damaged during operation. In one rotor, all the blades in the third and fourth stages had been sheared off and some had lifted from the dovetail portion of the drum. The damage in the other rotor was more extensive. Most of the blades in the first four stages had sheared off and many lifted from the dovetail region, particularly in the first two stages where several mounting dovetails had also fractured. Based on visual examination and the results of SEM fractography, metallography, and chemical analysis, investigators concluded that the compressor rotors failed due to stress-corrosion cracking in the dovetail mountings. They also provided recommendations to prevent or mitigate future occurrences.

This chapter provides an overview of the tools and techniques used to examine failure specimens and the wealth of information that can be obtained from fracture surfaces, cracks, wear patterns, and other such features. It discusses the use of metallography, fractography, and optical and electron microscopy. It presents a number of images recorded using these methods and explains what they reveal about the mode of fracture and the state of the component prior to failure.