Search Results for bulk formability

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.

An important activity in metalworking facilities is the testing of raw materials for characteristics that ensure the integrity and quality of the products made. This article reviews the common material parameters that can have a direct or indirect influence on workability and product quality. These include strength, ductility, hardness, strain-hardening exponent, strain-rate effects, temperature effects, and hydrostatic pressure effects. The article also reviews the material behavior characteristics typically determined by mechanical testing methods. It discusses various mechanical testing methods, including the tension test, plane-strain tension test, compression test, plane-strain compression test, partial-width indentation test, and torsion test. Aspects of testing particularly relevant to workability and quality control for metalworking processes are also described. Finally, the article details the various factors influencing workability in bulk deformation processes and formability in sheet-metal forming.

This article introduces the reasons behind the selection of a deformation process as the method of choice for producing a part or product form. It discusses the advantages, disadvantages, and categories of deformation processes. The article describes the major design considerations in applying a deformation process. Some fundamental aspects of plastic flow, flow stress, cold and hot working, workability, and formability are presented. The article provides information on free-surface cracking, central burst or chevron cracking, and cracking on die contact surface, as well as the microstructural effects on metal flow. It also discusses the defects in sheet-metal formed parts and flow-related defects in bulk forming.

Sheet forming comprises deformation processes in which a metal blank is shaped by tools or dies, primarily under the action of tensile stresses. This article discusses the classification of sheet-forming processes for obtaining desired dimensional features. It describes different process-related developments, namely, superplastic forming of aluminum, forming of tailor-welded blanks, rubber-pad forming, and high-velocity metal forming. The article explains cost-effective approaches of evaluating tooling designs prior to the manufacture of expensive steel dies and dieless forming techniques such as thermal forming and peen forming. It provides information on the application of advanced high-strength steels, magnesium alloys, and various ultrafine-grain materials for superplastic sheet forming. The article concludes with information on the development and application of simulation, design, and control of sheet-forming processes.

Characteristics of stainless steel that affect its formability include yield strength, tensile strength, and ductility, in addition to the effect of work hardening on these properties. This article discusses the forming process of stainless steel, heat-resistant alloys and refractory metals, detailing the major aspects of forming, including formability, lubrication, and forming methods and tools. The effect of factors such as alloy condition, cold reduction, forming direction (in the case of heat-resistant alloys) and temperature (in the case of refractory metals) on formability is also discussed.

This article discusses the advantages and limitations of drop hammer forming and presents the key factors for determining a process plan. It describes the characteristics of hammers and presents information on tool materials. It explains the use of lubricants and preparation of blanks for forming. The article also details the drop hammer forming process of steels, aluminum alloys, magnesium alloys, and titanium alloys.

This article provides an overview of some common sheet steel coatings available. It discusses the formability differences between coated and bare steel and provides some general guidelines on the forming of coated steels. Coated steels are classified according to the nature of the substrate, the type of coating, and the method used for its application. The article describes various coating types for steels such as zinc-coated steels, aluminum-coated steels, tin-coated steels, terne-coated steels, and organic-coated steels.

Many characteristics of extrusion alloy 6063 are similar to those of 6061 with slightly better formability and general corrosion resistance. This datasheet provides information on composition limits, fabrication characteristics, processing effects on physical and mechanical properties, mill product specifications, and applications of this 6xxx series alloy. The characteristics of alloy 6063 are compared with related alloys and tempers.

This article discusses the key factors that influence the selection of engineered materials for a particular application. Materials properties such as ultimate tensile strength, yield strength, hardness, and ductility, which chiefly define the performance or functional characteristics, are covered. This is followed by manufacturing process considerations such as material factors, shape factors, process factors, and the characteristics of fabricability, namely formability, workability, castability, machinability, and weldability.

This article emphasizes the traits that are common to high-velocity forming operations. It describes general principles on how metal forming is accomplished and analyzed when inertial forces are large. The article discusses the principal methods of high-velocity forming, such as explosive forming, electrohydraulic forming, and electromagnetic forming. It provides examples that illustrate how these methods can be practically applied. The article concludes with information on the status and development potential for the technology.

The selection of the best material for a particular design is intimately associated with the decisions of how to process the material or manufacture a part. This article describes the basic characteristics of manufacturing processes such as material factors, shape factors, and process factors. The influence of materials on the manufacturing cost is described with a specific example. The article discusses the design for manufacturability to minimize the total number of parts, use readily processed materials, and eliminate machining and finishing operations. It reviews the factors influencing the selection of a material for production, including material composition, heat-treated condition, surface finish, and cost of material. The article describes the material characteristics, such as terms formability, workability, castability, machinability, and weldability, that aid or hinder the production of a part without defects.

This article focuses on the industrial applications of phase diagrams. It presents examples to illustrate how a multicomponent phase diagram calculation can be readily useful for industrial applications. The article demonstrates how the integration of a phase diagram calculation with kinetic and microstructural evolution models greatly enhances the power of the CALPHAD approach in materials design and processing development. It also discusses the limitations of the CALPHAD approach.

Forming processes can be divided into three major categories: bulk forming, sheet-metal forming, and semisolid forming and polymer extrusion. This article introduces each process category with a description of the constitutive models. It outlines the required properties for process modeling and describes the test methods for determining these properties. The article discusses several compression tests used to determine stress-strain curves for bulk forming and tensile tests used to obtain stress-strain curves for sheet-metal forming. The article concludes with information on the measurement of viscosity of semisolid alloy materials by using three types of viscometers: the coaxial cylinder viscometer, the cone-and-plate viscometer, and the capillary viscometer.

Addition of beryllium, up to about 2 wt″, produces dramatic effects in copper, nickel, aluminum, magnesium, gold, zinc, and other base metal alloys. This article provides information on the chemical composition, microstructure, heat treatment, fabrication characteristics, production steps and physical metallurgy of beryllium-copper, beryllium-nickel, and beryllium-aluminum alloy, and tabulates their mechanical, electrical and physical properties, and temper designations. It describes the important features of this alloy group, including information on safe handling. Additionally, the article presents examples of the beneficial properties of beryllium-copper alloys and quantifies some of the major reasons for their selection for particular applications.

Compared to cold-formed parts, age-formed parts have lower residual stresses and consequently better stress corrosion resistance. This article addresses the technical issues that arise in the investigations of creep in precipitate-strengthened materials. The issues addressed help in developing alloys and tempers particularly suited for the age-forming process. The different steps involved in the program for predicting the final part shape are discussed. These basic steps involve developing mechanical tests to study creep at low temperatures and low stresses, describing low-temperature creep in terms of a constitutive model, and then using the constitutive model in a process model or finite element analysis to predict the final part shape.

Cold heading is typically a high-speed process where a blank is progressively moved through a multi-station machine. This article discusses various cold heading process parameters, such as upset length ratio, upset diameter ratio, upset strain, and process sequence design. It describes the various components of a cold-heading machine and the tools used in the cold heading process. These include headers, transfer headers, bolt makers, nut formers, and parts formers. The article explains the operations required for preparing stock for cold heading, including heat treating, drawing to size, machining, descaling, cutting to length, and lubricating. It lists the advantages of the cold heading over machining. Materials selection criteria for dies and punches in cold heading are also described. The article provides examples that demonstrate tolerance capabilities and show dimensional variations obtained in production runs of specific cold-headed products. It concludes with a discussion on the applications of warm heading.

Two high-strength low-alloy (HSLA) families, acicular-ferrite steels and pearlite-reduced steels, contain microalloying additions of vanadium and niobium. Vanadium, niobium, and titanium combine preferentially with carbon and/or nitrogen to form a fine dispersion of precipitated particles in the steel matrix. This article summarizes the metallurgical effects of vanadium, niobium, molybdenum, and titanium. The metallurgical fundamentals were first applied to forgings in the early 1970s. The ultimate strength of first- and second-generation microalloy steels is adequate for many engineering applications, but these steels do not achieve the toughness of conventional quenched and tempered alloys under normal hot-forging conditions. Third-generation microalloy steels differ from their predecessors in that they are direct quenched from the forging temperature to produce microstructures of lath martensite with uniformly distributed temper carbides. Without subsequent heat treatment, these materials achieve properties, including toughness, similar to those of standard quenched and tempered steels.

Alloy 5454 is an Al-Mg-Mn-Cr solid solution alloy with relatively high strength used for handling chemicals at elevated temperatures in the chemical and process industries. This datasheet provides information on key alloy metallurgy, processing effects on physical and mechanical properties, and fabrication characteristics of this 5xxx series alloy.

This article begins with a general review of the effects of changes in stress state on processing of materials. It describes the fundamentals of hydrostatic extrusion and reviews the various issues and benefits associated with hydrostatic extrusion. The article discusses the hydrostatic extrusion of structural alloys, composites, brittle materials, and intermetallics or intermetallic compounds, with examples. It concludes with a discussion on the attempts made to extend the hydrostatic extrusion to higher temperatures.