Search Results for heavy cutting

Oxyfuel gas cutting (OFC) includes a group of cutting processes that use controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. This article discusses the operation principles and process capabilities of the OFC. It reviews the properties and compositions of fuel types such as acetylene, natural gas, propane, propylene, and methyl-acetylene-propadiene-stabilized gas. The article describes the effects of OFC on base metal, including carbon and low-alloy steels, cast irons, and stainless steels. It provides information on light cutting, medium cutting, heavy cutting, and stack cutting. The article informs that the basic oxyfuel method can be modified to allow gas cutting of metals, such as stainless steel and most nonferrous alloys, that resist continuous oxidation.

Oxyfuel gas cutting (OFC) includes a group of cutting processes that use controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. This article provides a detailed discussion on the principles of operation and the process capabilities of OFC. In addition to providing information on the equipment used, the article describes the properties of fuel gases (acetylene, natural gas). It also presents an overview of the effect of OFC on base metal and explains the application of OFC in cutting thin, medium, and thick sections, bars, and structural and close-tolerance shapes.

Refractory metals are typically processed from powders into ingots that are subsequently swaged into round bars or rolled into plates. Secondary operations are required to fabricate more complex refractory metal components. This article discusses two such secondary operations, namely, machining and joining processes for tungsten, tungsten heavy alloys, molybdenum, tantalum, niobium, and rhenium components. It describes the various types of metal joining processes, including mechanical fastening, brazing, and welding.

Nickel-base alloys can be machined by techniques that are used for iron-base alloys. This article discusses the effects of distortion and microstructure on the machinability of nickel alloys. It tabulates the classification of nickel alloys based on machining characteristics. The article describes the machining operations performed on nickel alloys, such as turning, planing and shaping, broaching, reaming, drilling, tapping and threading, milling, sawing, and grinding. It provides information on the cutting fluids used in the machining of nickel alloys. The article also analyzes nontraditional machining methods that are suitable for shaping high-temperature, high-strength nickel alloys. These include electrochemical machining, electron beam machining, and laser beam machining.

This article discusses various machining techniques of zinc alloy die castings. These include turning, boring, drilling, reaming, tapping, die threading, milling, and sawing. In addition, the article describes the factors that influence machinability of the zinc alloy die castings.

Boring is a machining process in which internal diameters are generated in true relation to the centerline of the spindle by means of single-point cutting tools. This article provides a discussion on boring machines and boring tools and presents a comprehensive discussion on the various elements of boring. The elements are composition and hardness of workpiece metal, cutting fluid, speeds and feeds, and methods for piloting and supporting tools in boring applications. The article explains the role of workpiece size in selecting the equipment and processing procedure and the use of techniques to overcome difficulties presented by workpiece configuration. It describes the factors related to accuracy of boring and factors affecting them. The article also presents a discussion on close-tolerance boring and methods of controlling vibration and chatter. It concludes with a section presenting information on the use of boring equipment for machining operations other than boring.

Planing is a machining process for removing metal from surfaces in horizontal, vertical, or angular planes. This article discusses the process capabilities of planing and the operations of double-housing and open-side planers. It reviews workpiece setup procedures, including platelike workpieces, irregularly shaped workpieces, and workpieces used for tandem planning. The article provides information on the applications of high-speed steels and carbides in planer tools. It analyzes the tools available in a variety of configurations suited to the undercutting, slotting, and straight planing of either horizontal or vertical surfaces. These include carbide roughing, finishing, gooseneck-holder finishing, and double-cutting tools. The article lists recommended speeds and feeds for planing with high-speed steel or carbide tools. It concludes with a comparison of planing with sawing and milling.

Cutting fluids play a major role in increasing productivity and reducing costs by making possible the use of higher cutting speeds, higher feed rates, and greater depths of cut. After listing the functions of cutting fluids, this article then covers the major types, characteristics, advantages and limitations of cutting and grinding fluids, such as cutting oils, water-miscible fluids, gaseous fluids, pastes, and solid lubricants along with their subtypes. It discusses the factors considered during the selection of cutting fluid, focusing on machinability (or grindability) of the material, compatibility (metallurgical, chemical, and human), and acceptability (fluid properties, reliability, and stability). The article also describes various application methods of cutting fluids and precautions that should be observed by the operator.

Magnesium is machined in low-volume production on small, manually operated machine tools and on large, specially built, completely automated transfer machines operating at high production rates. This article focuses on the factors that affect the machining of magnesium. It discusses chip formation and distortion due to thermal expansion, cold work, and clamping and provides information on magnesium-matrix composites. The article describes materials, design, and sharpness as factors for selection of tool for machining magnesium. It illustrates turning and boring, planing and shaping, broaching, drilling, reaming, counterboring, milling, sawing, and grinding operations performed on magnesium. Safety measures related to machining, handling of chips and fines, and fire extinguishing are also discussed.

This article describes the principles of operation, operating techniques, equipment selection, and important process variables of air-carbon arc cutting. It also provides information on the safety practices to be followed during the air-carbon arc cutting process.