Search Results for ferrite deformation

The processing of steel involves five distinct sets of texture development mechanisms, namely, austenite deformation, austenite recrystallization, gamma-to-alpha transformation, ferrite deformation, and static recrystallization during annealing after cold rolling. This article provides an introduction on crystallographic textures. It discusses the effects of austenite rolling and recrystallization on the texture and transformation behavior of recrystallized austenite and deformed austenite. The article illustrates the overall summary of the rolling and transformation behavior. It details cold-rolling textures, annealing textures, and recrystallization textures of steel samples. The article concludes with a summary of texture development during cold rolling and annealing.

Thermomechanical processing (TMP) refers to various metal forming processes that involve careful control of thermal and deformation conditions to achieve products with required shape specifications and good properties. This article describes TMP methods in producing hot-rolled steel and reviews how improvements in the strength and toughness depend on the synergistic effect of microalloy additions and on carefully controlled thermomechanical conditions. It discusses TMP variables and the general distinctions between conventional hot rolling and common types of controlled-rolling schedules. The article describes the metallurgical processes in grain refinement of austenite steel by hot working, such as recovery and recrystallization and strain-induced transformation. The grain refinement in high strength low alloy steel by alloy addition is also discussed. The article provides an outline on the key stages of deformation, and the required metallurgical information at each of these stages.

This article is an atlas of fractographs that covers pearlitic and ferritic ductile irons. The fractographs display the following: brittle cleavage fracture; fatigue crack propagation; fatigue and monotonic fracture surfaces; fracture modes in slow monotonic loading and impact loading; and microcrack initiation and propagation.

This article reviews various phases and constituents found in the microstructures of low-carbon and coated steels. It provides information on the criteria for selecting proper metallographic procedures. Techniques used to prepare metallographic specimens of low-carbon steels and coated steels, such as sectioning, mounting, grinding, polishing, and etching, are discussed. The article also reviews the simple and proven manual sample preparation techniques of coated steel specimens.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of pearlitic malleable and ferritic malleable white irons, and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the fracture sequence, localized plastic deformation, and microcrack initiation and propagation of these irons.

This article describes metallographic preparation and examination techniques for stainless steels and maraging steels. It presents a series of micrographs demonstrating microstructural features of these alloys. Procedures used to prepare stainless steels for macroscopic and microscopic examination are similar to those used for carbon, alloy, and tool steels. Cutting and grinding must be carefully executed to minimize deformation because the austenitic grades work harden readily. The high-hardness martensitic grades that contain substantial undissolved chromium carbide are difficult to polish while fully retaining the carbides. Unlike carbon, alloy, and tool steels, etching techniques are more difficult due to the high corrosion resistance of stainless steels and the various second phases that may be encountered. The microstructures of stainless steels can be quite complex. Matrix structures vary according to the type of steel, such as ferritic, austenitic, martensitic, precipitation hardenable, or duplex.

This article describes microstructures and microstructure-property relationships in steels. It emphasizes the correlation of microstructure and properties as a function of carbon content and processing in low-alloy steels. The article discusses the iron-carbon phase diagram and the phase transformations that change the structure and properties at varying levels of carbon content. Microstructures described include pearlite, bainite, proeutectoid ferrite and cementite, ferrite-pearlite, and martensite. The article depicts some of the primary processing steps that result in ferrite-pearlite microstructures. It shows the range of hardness levels which may be obtained by tempering at various temperatures as a function of the carbon content of the steel. To reduce the number of processing steps associated with producing quenched and tempered microstructures, new alloying approaches have been developed to produce high-strength microstructures directly during cooling after forging.

This article discusses the bulk formability or workability of steels. It describes their formability characteristics and presents procedures for various formability tests used for carbon and alloy steels. Tests for bulk formability can be divided into two main categories: primary tests and specialized tests. The article compares the processing of microalloyed plate and bar products. The article focuses on the use of torsion testing to evaluate the forgeability of carbon and alloy steels and presents information on measuring flow stress. The article discusses the metallurgy and thermomechanical processing of high-strength low-alloy (microalloyed) steels and the various parts of the rolling operation. The article summarizes some of the common tests for determining formability in open-die and closed-die forgings.

This article describes a method to predict mechanical properties of cast iron materials and illustrates how to use the predictions in computer-aided tools for the analysis of castings subjected to load. It outlines some ways to predict the hardness and elastic modulus of cast iron without going into dislocation theory. The article discusses modeling of hardness in cast iron based on a regular solution equation in which the properties of each phase depend on chemical composition and coarseness. It describes the evaluation of material parameters from the tensile stress-strain curve. The article concludes with an illustration of a finite-element method (FEM) model containing heterogeneous mechanical properties using local material definitions.

In cast iron, residual stresses normally arise due to hindered thermal contraction, meaning that they are associated with the presence of constraints that prevent the natural, free volumetric variation of the material upon solid-state cooling. This article explains their mechanism of formation by introducing the scalar relation, known as the additive strain decomposition. The main factors influencing casting deformation are volume changes during solidification and cooling, phase transformations, alloy composition, thermal gradients, casting geometry, and mold stability. The article reviews the dimensional stability in cast iron and discusses macroscopic and microscopic stresses in cast iron.

The warm and hot working of metals provide the ability to shape important materials into component shapes that are useful in a variety of applications requiring strength, toughness, and ductility. This article focuses on a variety of metals that can be hot or warm worked, and describes the characteristics and processing considerations of each metal. It discusses forging because it is a versatile metalworking process and performed at cold, warm, and hot working temperatures. The article also presents the applications of steels, stainless steels, aluminum alloys, titanium alloys, superalloys, and copper alloys.

Machining of cast iron involves removing metal from the cast part, usually by cutting with a power-driven machine tool. This article discusses the factors that influence machinability, the methods used to evaluate machinability of cast irons, the effects of cast iron microstructure on cutting tool life, and the importance of as-cast surface integrity on the machining variation. It presents examples of cutting tool materials selection for different cast iron grades, and describes the effects of coolants on the machining of cast irons. A chart showing different cutting materials and cutting speed ranges for selected iron-carbon alloys is also presented. Different types of cutting tool wear observed during turning are schematically illustrated.