Search Results for flat-die rolling

This article discusses the three characteristics that are important in evaluating and selecting metals for thread rolling, namely, rollability, flaking, and seaming. It reviews the capabilities and limitations of flat-die rolling, radial-infeed rolling, tangential rolling, through-feed rolling, planetary thread rolling, continuous rolling, and internal thread rolling, as well as the rolling machines and dies used. The article describes the factors affecting die life and provides information on radial die load, seam formation, surface finish, and thread dimensions that are affected by the form of the thread. It explains the reasons for using fluids in thread rolling. The article concludes with a comparison of rolling with cutting and grinding.

Thread rolling is a cold-forming process for producing threads or other helical or annular forms by rolling the impression of hardened steel dies into the surface of a cylindrical or conical blank. Methods that use cylindrical dies are classified as radial infeed, tangential feed, through feed, planetary, and internal. This article focuses on the capabilities, limitations, and machines used for these methods. It describes the three characteristics, such as rollability, flaking, and seaming, used in evaluating and selecting metals for thread rolling. The article explores the factors affecting die life and explains the effect of thread form on processing. It provides information on various fluids used in thread rolling to cool the dies and the work and to improve the finish on the rolled products. The article provides a comparison between thread rolling and cutting, as well as between thread rolling and grinding.

Open-die forging can be distinguished from most other types of deformation processes in that it provides discontinuous material flow as opposed to continuous flow. This article describes the equipment and auxiliary tools used in open-die forging. It discusses the production and practice of open-die forging, with some practical examples. The article illustrates macrosegregation in a large steel ingot and lists the forgeable alloys. It reviews the physical and mathematical models used in deformation modeling. The article explains the contour forging and roll planishing process. It inform that to ensure that forgings can be machined to correct final measurements, it is necessary to establish allowances, tolerances, and specifications for flatness and concentricity. The article also tabulates the allowances and tolerances for as-forged shafts and bars.

This article describes the zinc and zinc alloys for decorative and functional applications. It focuses on the types of zinc coatings, namely, hot dip galvanizing, electrogalvanizing, metallizing, and mechanical galvanizing. The article covers the uses of zinc alloy castings, including pressure die castings, and gravity castings. It details the wrought products of zinc and zinc alloys, including flat-rolled products, wire-drawn products, extruded products, and forged products. The article also describes various properties of zinc alloys, including mechanical, thermal, electrical, chemical, and magnetic properties. The listing for each alloy includes chemical compositions, relevant specifications, mass characteristics, and fabrication characteristics.

This article presents formulas for calculating the following: effective stress, strain, and strain rate (isotropic material) in arbitrary coordinates and in principal coordinates; compression testing, tension testing, and torsion testing of isotropic material; and Barlat's anisotropic yield function Yld2000-2d for plane-stress deformation of sheet material. It also contains formulas related to flat (sheet) rolling, conical-die extrusion, wire drawing, bending, and deep drawing of cups from sheet metal.

This article contains nine tables that present useful formulas for deformation analysis and workability testing. The tables present formulas for effective stress, strain, and strain rate in arbitrary coordinates, principal, compression and tension testing of isotropic material. The article also provides formulas for flat rolling, conical-die extrusion, wire drawing, deep drawing of cups from sheet metal, and bending, and formulas for anisotropic sheet materials.

This article provides information on the properties, compositions, designations, and applications of zinc and zinc alloys. It discusses the principal areas of application of zinc: in coatings and anodes for corrosion protection of irons and steels; in zinc casting alloys; as an alloying element in copper, aluminum, magnesium, and other alloys; in wrought zinc alloys; and in zinc chemicals. The zinc coating applications of hot dip galvanizing, electrogalvanizing, plating, and thermal spray are presented. The use of zinc alloys in both gravity and pressure die castings is discussed as well as the three main types of wrought products: flat-rolled products, wire-drawn products, and extruded and forged products. The article also provides a section on the corrosion resistance of zinc and zinc coatings in various atmospheres.

This article is a comprehensive collection of tables containing formulas for metals processing, namely, casting and solidification, flat (sheet) rolling, conical-die extrusion, wire drawing, bending, and deep drawing. Formulas for compression, tension, and torsion testing of isotropic materials are included. The article also lists the formulas for effective stress, strain, and strain rate (isotropic material) in arbitrary and principal coordinates; dimensionless groups in fluid mechanics; and anisotropic sheet materials at various loading conditions.

Roll forging is a process for simultaneously reducing the cross-sectional area and changing the shape of heated bars, billets, or plates. This article provides an overview of the process capabilities, production techniques, machines and machine size selection considerations, and types of roll dies and auxiliary tools for the roll forging. It concludes with information on the production examples of roll forging.

This article describes the extrusion process, which converts soft, plastic material into a particular form using an extruder, or screw conveyer. It discusses the two main types of plastic extruders, twin-screw and single-screw, estimation of extruder capacity, and design and operations (heating, cooling, downstream sizing, corrugating, and crossheading) of the screw, the most important component of any extruder. It discusses the shapes produced by screw extrusion and the types of extrusion products produced by extrusion processes, including blown-film extrusion, flat-film or sheet extrusion, chill-roll film extrusion, pipe or tube extrusion, wire and cable coverings, extrusion coating, and profile extrusion, and provides some discussion on multiple-screw extruders. The article describes the dimensional accuracy of extrusion products, and lists common defects that occur frequently in the extrusion process.

This article discusses the presses, auxiliary equipment, and dies used in the blanking and piercing of commonly used magnetically soft materials, namely, low-carbon electrical steels and oriented and nonoriented silicon electrical steels. It describes the effect of stock thickness and work metal composition and condition on blanking and piercing. The article provides an overview of the influence of burr height on stacking factors and presents a discussion on the lubrication and core plating of electrical steels that ease the process.

This article focuses on approximate closed-form analytical methods, such as slab and upper bound methods, used for forward and inverse design of metal forming problems. Selected examples of application of these methods to metal forming processes are also discussed.

This article describes various bending methods: draw bending, compression bending, roll bending, stretch bending, and ram-and-press bending. It discusses the machines used for the bending of bars. These machines include devices and fixtures for manual bending, press brakes, conventional mechanical and hydraulic presses, horizontal bending machines, rotary benders, and bending presses. The article illustrates the tools used in bending and other bending process. It also tabulates the lubricants required for bending specific metals.

This article is a compilation of definition of the terms related to modeling for metals processing.

This article describes the effect of temperature, composition, strain rate, and fabrication history on the results obtained in the forming of beryllium as well as the safety measures required. It provides information on the equipment, tooling, dies, and workpieces used for forming beryllium. The article discusses the role of lubrication, blank development, tool designs, and strain rates, in deep drawing. It also provides information on the tooling and applications of three-roll bending, stretch forming, and spinning.

This article reviews the selection and formability characteristics of steels, with an emphasis on low-carbon steels and some coverage on the forming of high-carbon steels. It describes the key factors that affect the formability of steels in terms of steelmaking practices, surface finishes, metal thicknesses, and alloying. The article explains the bending and forming operations with some examples. It also describes the formation of various shells, including doubly contoured shells, deep recessed shells, and deep circular shells.