Search Results for continuous 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.

This article provides general information on the definition, purposes, and quench equipment for direct-forge quenching (DFQ) and direct heat treatment (DHT) processes that are widely used in automotive and various other mechanical industries. It discusses the technological advances in these processes and their ability to produce high-quality components at low production cost from microalloyed steels. Further, the article describes the influence of carbon contents on toughness of microalloyed direct heat treated steels. It focuses on the DFQ and DHT steel technologies applied in continuous rolling mills to produce various DHT steels for machining and cold forming applications.

Roll welding (ROW) is a process in which two or more sheets or plates are stacked together and then passed through the rolls until sufficient deformation has occurred to produce solid-state welds. This article begins with a process description of two modes of roll welding, including pack rolling. It describes a patented roll welding process for fabrication of heat exchangers. The article presents a table showing the typical properties of common roll welded clad laminates. The relative weldability of selected dissimilar metals and alloys roll welded into clad-laminate form are also tabulated. The article concludes with information on cladding of metals by strip roll welding.

Contour roll forming is a continuous process for forming metal from sheet, strip, or coiled stock into desired shapes of uniform cross section by feeding the stock through a series of roll stations equipped with contoured rolls. This article discusses the materials, roll-forming machines, tooling, and auxiliary equipment used in contour roll forming and its process variables. Tooling used in roll forming includes forming rolls and dies for punching and cutting off the material. The article discusses the additional tooling required in tube mills to weld, size, and straighten the tubes as they are produced on the machine. It describes the roll design for tube rolling and reviews the seam welding operations of pipe and tubing. The article discusses cross-sectional tolerances, the reshaping of round tubing, and factors that affect the quality, accuracy, and surface finish.

Ingot casting is the vital conduit between molten metal provided by primary production and recycling and the manufacture of aluminum and aluminum alloy products. A number of ingot casting processes have been developed to ensure the soundness, integrity, and homogeneity required by downstream manufacturing processes. This article starts with a review of the different forms of ingot and the molten-metal processing techniques involved in ingot casting. It then describes the open-mold casting and direct chill (DC) ingot casting processes. The process variations and solidification in the DC process are summarized. The article explains continuous processes, namely, twin-roll strip casting, slab casting, and wheel-belt processes. It concludes with information on postsolidification processes, including stress relief and scalping, and a discussion of safety practices for ingot casting.

Ingot casting is the vital conduit between molten metal provided by primary production and recycling, and the manufacture of aluminum and aluminum alloy products. This article discusses various ingot forms, such as remelt ingot, billets, ingots for rolling, fabricating ingot, and particle ingot and powder. It describes the molten metal processing and ingot casting process in terms of open-mold casting and direct chill process. The article examines the continuous processes that provide commercial alternatives to conventional ingot casting. It reviews the postsolidification processes in terms of stress relief, homogenization, and scalping. The article concludes with a discussion on safety limited to ingot casting.

Direct powder rolling (DPR) is a process by which a suitable powder or mixture of powders is compacted under the opposing forces of a pair of rolling mill rolls to form a continuous green strip that is further densified and strengthened by sintering and rerolling. This article discusses the basic principle, process considerations, and advantages of DRP, and describes the application of this process in the manufacture of powder titanium and titanium alloy components. It further illustrates the complexity of the process and describes the benefits of using DRP in terms of economics and product quality.

The handling of billets or bars is an essential part of an induction heating system. This article describes two types of handling systems available for bar heating lines: inclined ramps with escapement, and sling feeder with inclined ramp and escapement. It focuses on the various infeed billet handling systems such as bin tippers, elevator feeders, rotary feeders, vibratory bowl feeders, magazine loaders, and rod feeders. The article provides information on the main categories of billet feeding systems, namely, dual pinch roll drive assemblies, tractor drive assemblies, billet pusher systems, walking beam assemblies, and index/continuous conveyor systems. It also discussed the hot billet handling systems used to deliver heated billets to the forging cell. These methods include billet extractor conveyors, accept/reject systems with pyrometer measurements, extractor rolls, discharge chutes, pinch roll extractors, pick-n-place systems, and robots.

This article presents a detailed account on the process flow, composition, alternative sources, and the advancement of ironmaking, steelmaking and secondary steelmaking practices. Some steels, such as bearing steels, heat-resistant steels, ultrahigh strength missile and aircraft steels, and rotor steels have higher quality requirements and tighter composition control than plain carbon or ordinary low-alloy steels. The production of special-quality steels requires vacuum-based induction or electric remelting and refining capabilities. The article explores the types and characteristics of various steel manufacturing processes, such as ingot casting, continuous casting, and hot rolling. It provides an outline of specialized processing routes of producing ultralow plain carbon steels, interstitial-free steels, high strength low-alloy steels, ultrahigh strength steels, stainless steels, and cold-rolled products, and briefly explains the analytical techniques for liquid steels.

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.

This article describes two methods based on rolling of sheet. The first is roll welding, where two or more sheets or plates are stacked together and then passed through rolls until sufficient deformation has occurred to produce solid-state welds. The other is laser roll welding, which is a hybrid process based on a thin-melting interface for a lap joint of dissimilar-metal sheets using a roller and one-sided laser heating. The article discusses the types, advantages, and applications of roll welding and laser roll welding. It also provides a detailed discussion on the laser roll welding of dissimilar metals.

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 provides an overview of the classification system of coppers for conductors and for wires and cables, as well as wire rod fabrication techniques such as rolling and continuous casting. Wiredrawing and wire stranding operations, including the preparation of rod surface, drawing, production of flat rectangular wire, annealing, and coating, are discussed. The article also provides information on electrical insulation and jacketing techniques, including polymeric insulation, enamel insulation, and paper-and-oil insulation.

Thermal spray is an important surface-modification process implemented by the steel industry. This article reviews thermal spray materials and equipment used and also provides examples of where typical coated components result in improved performance. It contains a table that lists thermal spray applications in the iron-steel manufacturing industry.

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.