Search Results for pearlite banding

This chapter describes some of the most effective tools for investigating boiler tube failures, including scanning electron microscopy, optical emission spectroscopy, atomic absorption spectroscopy, x-ray fluorescence spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. It explains how the tools work and what they reveal. It also covers the topic of image analysis and its application in the measurement of grain size, phase/volume fraction, delta ferrite and retained austenite, inclusion rating, depth of carburization/decarburization, scale thickness, pearlite banding, microhardness, and hardness profiles. The chapter concludes with a brief discussion on the effect of scaling and deposition and how to measure it.

This chapter covers a broad range of low-carbon steels optimized for structural applications. Low-carbon structural steels are generally considered the highest-strength steels that can be welded without undue difficulty, even in the field. They include mild steels, carbon-manganese and niobium- and vanadium-containing steels, and high-strength low-alloy steels. Chapter 5 discusses the composition, microstructure, and properties of these workhorse materials and explains how to identify the cause of production-related issues such as lamellar tearing and ferrite-pearlite banding. It also describes some of the alloying variations that have been developed to improve machinability and the mechanisms by which they work.

Inclusions and chemical segregation are factors in many process-induced failures involving steel parts. Inclusions are nonmetallic compounds introduced during production; segregation is a type of chemical partitioning that occurs during solidification. This chapter discusses the origins of segregation and inclusions and their effect on the mechanical properties and microstructure of steel. It explains how to identify various types of inclusions and characteristic segregation patterns, such as banding. It also describes the effect of hot work processing on solidification structure and the chemical variations produced by interdendritic segregation.

This chapter examines the microstructure and properties of annealed and normalized steels containing more than 0.25% carbon. It shows, using detailed micrographs, how incrementally higher levels of carbon affect the structure and distribution of pearlite and how it intermingles with proeutectoid ferrite and cementite. It explains how ferrite and pearlite respond to deformation and how related features such as slip lines, dislocations, shear bands, and kinking can be detected as well as what they reveal. It also describes the structure of patented wires, cast steels, and sintered steels and the morphology of manganese sulfide inclusions in castings.