Search Results for hemming

This chapter begins with a review of the mechanics of bending and the primary elements of a bending system. It examines stress-strain distributions defined by elementary bending theory and explains how to predict stress, strain, bending moment, and springback under various bending conditions. It describes the basic principles of air bending, stretch bending, and U- and V-die bending as well as rotary, roll, and wipe die bending, also known as straight flanging. It also discusses the steps involved in contour (stretch or shrink) flanging, hole flanging, and hemming and describes the design and operation of press brakes and other bending machines.

This appendix is a glossary of terms and definitions associated with sheet metal forming.

This chapter provides a concise, design-oriented summary of more than 30 sheet forming processes within the categories of bending and flanging, stretch forming, deep drawing, blank preparation, and incremental and hybrid forming. Each summary includes a description and diagram of the process and a bullet-point list identifying relevant equipment, materials, variations, and applications. The chapter also discusses critical process variables, interactions, and components and the classification of sheet metal parts based on geometry.

This chapter reviews the causes and cases associated with the problems originated by tempering of steels. To provide background on this phenomenon, a brief description of the martensite reactions and the steel heat treatment of tempering is given to review the different stages of microstructural transformation. A section describing the types of embrittlement from tempering, along with mechanical tests for the determination of temper embrittlement (TE), is presented. Various factors involved in the interaction of the TE phenomenon with hydrogen embrittlement and liquid-metal embrittlement are also provided. The cases covered are grinding cracks on steel cam shaft and transgranular and intergranular crack path in commercial steels.

This chapter describes the different aluminum products used to manufacture modern automobile components. It discusses how automakers use these products to reduce weight, improve performance, and manage production costs. It also reflects on the changes in the aluminum industry, automakers, and their relationships. Organized by product type—castings, sheet, and extrusions—each section of the chapter describes the relevant alloys, tempers, and properties required to meet specific needs for component parts and final assembly.

This chapter describes sheet metal forming operations, including cutting, blanking, piercing, and bending as well as deep drawing, spinning, press-brake and stretch forming, fluid forming, and drop hammer and electromagnetic forming. It also discusses the selection and use of die materials and lubricants along with superplastic forming techniques.

Any forming process that converts stored energy to plastic deformation in less than a few milliseconds is considered a high-velocity or impulse forming process. This chapter discusses the operating principles, equipment, and applications of the most common high-rate forming processes, including high-velocity hydroforming, high-velocity mechanical forming, and electromagnetic or energy-based forming.

Sulfur is one of the most common corrosive contaminants in high-temperature industrial environments and its presence can cause a number of problems, including sulfidation. This chapter describes the sulfidation behavior of a wide range of alloys as observed in three types of industrial environments. One environment consists of sulfur vapor, hydrocarbon streams, H2S, and H2-H2S gas; sulfides are the only corrosion products that form under these conditions. Another environment consists of H2, CO, CO2, H2S, and other gases, causing the formation of oxides as well as sulfides in most alloys. The third environment, for which less data exists, contains either SO2 or O2-SO2 mixtures.

The machinery and equipment required for rod and tube extrusion is determined by the specific extrusion process. This chapter provides a detailed description of the design requirements and principles of machinery and equipment for direct and indirect hot extrusion. It then covers the presses and auxiliary equipment for tube extrusion, induction furnaces for billet processing, handling systems for copper and aluminum alloy products, extrusion cooling systems, and age-hardening ovens. Next, the chapter describes the principles and applications of equipment for the production of aluminum and copper billets. Then, it focuses on process control in both direct and indirect hot extrusion of aluminum alloys without lubrication. The chapter describes the technology of electrical and electronic controls in the extrusion process. It ends with a discussion on the factors that influence the productivity and quality of the products in the extrusion process and methods for process optimization.

This chapter explains how to join beryllium parts using adhesive bonding and mechanical fastening techniques and discusses the advantages and disadvantages of each method. It describes the stresses that need to be considered when designing adhesive bonds, the benefits and limitations of different adhesives, and surface preparation requirements. It explains how adhesives are applied and cured and how curing times and temperatures affect bonding strength. It also discusses the use of bolts and rivets and the different types of joints that can be made with them.