Search Results for heat-treatable low-alloy steels

This article presents in-depth metallurgical information about the response of carbon and low-alloy steels to welding conditions and micro-structural evolution in the weld heat-affected zone. It discusses the fabrication weldability and service weldability of carbon and low-alloy steels. The article describes six general classes of the metal: low-carbon steels, high-strength low-alloy steels, quenched-and-tempered steels, heat-treatable low-alloy steels, thermal-mechanical-controlled processing steels, and chromium-molybdenum steels. It concludes with an illustration of steels' susceptibility to hydrogen-assisted cold cracking relative to carbon content and carbon equivalent.

This article discusses factors involved in selecting welding processes and consumables and establishing procedures and practices for the arc welding of low-alloy steels. It provides information on welding consumables in terms of filler metals and fluxes and shielding gases. The article describes the various categories of low-alloy steels, such as high-strength low-alloy (HSLA) structural steels, high-strength low-alloy quenched and tempered(HSLA Q&T) structural steels, low-alloy steels for pressure vessels and piping, medium-carbon heat-treatable (quenched and tempered) low-alloy (HTLA) steels, ultrahigh-strength low-alloy steels, and low-alloy tool and die steels. It concludes with a discussion on repair practices for tools and dies.

Brazing technology is continually advancing for a variety of metals including aluminum and its alloys and nonmetals. This article discusses the key physical phenomena in aluminum brazing and the materials for aluminum brazing, including base metals, filler metals, brazing sheet, and brazing flux. It describes various aluminum brazing methods, such as furnace, vacuum, dip, and torch brazing. Friction, flow, induction, resistance, and diffusion brazing are some alternate brazing methods discussed. The article reviews the brazing of aluminum to ferrous alloys, aluminum to copper, and aluminum to other nonferrous metals. It also discusses post-braze processes in terms of post-braze heat treatment and finishing. The article concludes with information on the safety precautions considered in brazing aluminum alloys.

Aluminum, a commonly used base material for brazing, can be easily fabricated by most manufacturing methods, such as machining, forming, and stamping. This article outlines non-heat-treatable wrought alloys typically used as base metals for the brazing process. It highlights chloride-active and fluoride-active types of fluxes that are used for torch, furnace, or dip brazing processes. The article explains the steps to be performed, including the designing of joints, preblaze cleaning, assembling, brazing techniques (dip brazing, furnace and torch brazing, fluxless vacuum brazing), flux removal techniques, and postbraze heat treatment processes. It concludes with information on the safety precautions to be followed during the brazing process.

Weldability is a function of three major factors: base material quality, welding process, and design. This article focuses on base-metal weldability of aluminum alloys in terms of mechanical property degradation in both the weld region and heat-affected zone, weld porosity, and susceptibility to solidification cracking and liquation cracking. It provides an overview on welding processes, including gas metal arc welding, gas tungsten arc welding, resistance spot and seam welding, laser beam welding, and various solid-state welding processes. A review on joint design is also included, mainly in the general factors associated with service weldability (fitness). The article also provides a discussion on the selection and weldability of non-heat-treatable aluminum alloys, heat treatable aluminum alloys, aluminum-lithium alloys, and aluminum metal-matrix composites.

This article focuses on the temperature requirements of typical nonferrous metals and their alloys of commercial importance. These include aluminum, copper, magnesium, and titanium. The article describes the thermoelectricity, photoelectricity, and capacity of aluminum alloys. In addition, it provides information on the electrical properties of copper and its alloys. The article also lists typical physical and mechanical properties of aluminum alloys at ambient temperature.

Aluminum alloys, particularly the heat-treatable alloys, are sensitive to weld cracking. Anticipation of these characteristics and general knowledge of these materials assist in selection of suitable method for welding heat-treatable aluminum alloys. This article provides a general description of the metallurgy, characteristics, and applications of heat-treatable aluminum alloys and a detailed discussion on the characteristics of heat-treatable aluminum alloys, their resulting impact on the weld quality and property, along with the methods of avoiding or reducing the impacts. The impact created in the weld quality includes crack sensitivity, liquation cracking, porosity, and heat-affected zone degradation. The article provides an overview of filler alloy selection for reducing weld crack sensitivity and increasing weld strength, ductility, and corrosion resistance in the welds of heat-treatable aluminum alloys.

Heat treatment of aluminum alloys frequently refers to the heat treatable aluminum alloys that can be strengthened by solution treatment, quenching, and subsequent hardening. This article introduces the general metallurgy of strengthening aluminum alloys by heat treatment. It discusses various heat treatable alloying elements, such as copper, chromium, iron, magnesium, silicon, zinc, and lithium. The article describes the age-hardening treatments and generalized precipitation sequence for aluminum alloys. It reviews the solution heat treatment in terms of solution heating time and temperature, as well as high-temperature oxidation. The article also discusses quench sensitivity, vacancy loss, grain-boundary precipitates, and quench delay for the heat treatment of aluminum. It concludes with a discussion on the deformation of aluminum alloys prior to aging.

Porcelain enamel is a fusion bonded glass coating that resists chemical and abrasive attack, provides thermal and electrical insulation, and improves aesthetic qualities. It is used on cast iron as well as steel and aluminum alloys. This article provides a review of the porcelain enameling process, the composition of frits, and the preparation of coating substrates. It also provides information on chemical, mechanical, and electrical properties and sheds light on process consistency and quality control.

This article describes the process features, advantages, limitations, and applications of the flux cored arc welding (FCAW) as well as the equipment used in the process. Base metals, namely, carbon and low-alloy steels, stainless steels, and nickel-base alloys, welded by the FCAW process are reviewed. The article illustrates the manufacturing process for the electrodes used in FCAW and outlines the classification of carbon and low-alloy steel, stainless steel, and nickel-base electrodes.

Aluminum and its alloys can be joined by as many or more methods than any other metal. This article discusses the properties of aluminum, namely hydrogen solubility, electrical conductivity, and thermal characteristics. It analyses the primary factors commonly considered when selecting a welding filler alloy. These include ease of welding or freedom from cracking, tensile or shear strength of the weld, weld ductility, service temperature, corrosion resistance, and color match between the weld and base alloy after anodizing. The article provides a detailed description of gas-shielded arc welding processes for welding of aluminum alloys and also reviews other welding processes such as oxyfuel gas welding and laser-beam welding.

Fracture of aluminum alloys can occur due to several failure types and/or fracture morphologies, including overload, intergranular fracture, fatigue, corrosion, and mixed-mode fracture. This article provides a detailed discussion on these failure types and/or fracture morphologies. It also presents the differences between wrought and cast aluminum products.

Friction welding (FRW) is a solid-state welding process that uses the compressive force of the workpieces that are rotating or moving relative to one another, producing heat and plastically displacing material from the faying surfaces to create a weld. This article reviews practice considerations for the two most common variations: inertia welding and direct-drive friction welding. Direct-drive friction welding differs from inertia welding, primarily in how the energy is delivered to the joint. The article discusses the parameter calculations for inertia welding and direct-drive friction welding. It provides information on friction welding of carbon steels, stainless steels, aluminum-base alloys, and copper-, nickel-, and cobalt-base materials.

This article describes the different types of precipitation and transformation processes and their effects that can occur during heat treatment of various nonferrous alloys. The nonferrous alloys are aluminum alloys, copper alloys, magnesium alloys, nickel alloys, titanium alloys, cobalt alloys, zinc alloys, and heat treatable silver alloys, gold alloys, lead alloys, and tin alloys. It also provides a detailed discussion on the effects due to precipitation and transformation processes in these non-ferrous alloys.

In the flux-cored arc welding (FCAW) process, the heat for welding is produced by an electric arc between a continuous filler metal electrode and a workpiece. This article discusses the advantages and disadvantages and applications of the FCAW process. It schematically illustrates the semiautomatic FCAW equipment used in the gas-shielded FCAW process. The article discusses the manufacture of flux-cored electrodes and the classification of electrodes, such as carbon and low-alloy steel electrodes, stainless steel electrodes, and nickel-base electrodes. The functions of common core ingredients in FCAW electrodes are listed in a table.

This article provides information on the practice considerations for the inertia and direct-drive rotary friction welding processes. It presents the tooling and welding parameter designs of these processes. The article discusses the welding of different material family classes to provide a baseline for initial development of a welding parameter set. Common material family classes, including steels, nonferrous metals, and dissimilar metals, are discussed.