Search Results for alloy classification

Stainless steels are primarily alloys of iron and chromium. They are grouped into five families, primarily based on their microstructure: ferritic, austenitic, martensitic, duplex, and precipitation hardening. Three out of the five families of stainless steels, namely, austenitic, ferritic, and martensitic, are well suited for manufacture via conventional powder metallurgy (PM) processes. This article presents the iron-chromium partial phase diagram to illustrate the changes in the temperature range when pure iron is alloyed with chromium. It describes AISI and UNS numbering systems, which are used as an identification system for stainless steels. The article tabulates the material designations of stainless steels in accordance with the Metal Powder Industries Federation. It also details the characteristics and chemical composition of wrought and PM stainless steels.

This article addresses classifications and designations for carbon steels and low-alloy steels, particularly high-strength low-alloy (HSLA) steels, based on chemical composition, manufacturing methods, finishing method, product form, deoxidation practice, microstructure, required strength level, heat treatment and quality descriptors. It describes the effects of alloying elements on the properties and characteristics of steels. The article provides extensive tabular data pertaining to domestic and international designations of steels.

This article provides an overview of the different classification and designation systems of wrought carbon steel and alloy steel product forms with total alloying element contents not exceeding 5″. It lists the quality descriptors, chemical compositions, cast or heat composition ranges, and product analysis tolerances of carbon and alloy steels. The major designation systems discussed include the Society of Automotive Engineers (SAE)-American Iron and Steel Institute (AISI) designations, Unified Numbering System (UNS) designations, American Society for Testing and Materials (ASTM) designations, Aerospace Material Specification (AMS), and other international designations and specifications.

Submerged arc welding (SAW) is an arc welding process in which the arc is concealed by a blanket of granular and fusible flux. This article provides a schematic illustration of a typical setup for automatic SAW and discusses the advantages and limitations and the process applications of SAW. The article discusses flux classification relative to production method, relative to effect on alloy content of weld deposit, and relative to basicity index. It describes the procedural variations and the effect of weld current, weld voltage, electrical stickout, travel speed, and flux layer depth on weld bead characteristics. The article concludes with information on weld defects, such as lack of fusion, slag entrapment, solidification cracking, hydrogen cracking, or porosity.

Magnetically soft materials are characterized by their low coercivity, an essential requirement for irons and steels selected for any application involving electromagnetic induction cycling. This article provides information on ferromagnetic material properties and how they are affected by impurities, alloying additions, heat treatment, residual stress, and grain size. It also describes classification and testing methods for magnetically soft materials such as high-purity iron, low-carbon steels, silicon steels, iron-aluminum alloys, nickel-iron alloys, iron-cobalt alloys, ferrites, and stainless steels. The article also addresses corrosion resistance and provides insights on the selection of alloys for power generation applications, including motors, generators, and transformers. A short note on the design and fabrication of magnetic cores is also included.

This introductory article provides basic information on the various aspects of solid-state transformation: multiphase microstructures, substructures, and crystallography, which assist in characterizing the morphology of phase transformations. It contains a flowchart that illustrating the classification of transformations by growth processes.

This article discusses the effects of brazing temperature and thermal treatment on structure and mechanical behavior of different classes of titanium base metals such as commercially pure (CP) titanium, alpha or near-alpha alloys, alpha-beta alloys, and beta alloys. The classification, properties, and potential heat treatment of titanium base alloys are presented in tables. The article provides information on brazed joints of titanium with carbon steels, as well as ceramics and graphite. It discusses the risks involved in titanium brazing, including erosion of base metal, brittle intermetallics, and low ductility. The article reviews induction and torch brazing, infrared brazing, diffusion brazing, and brazing by heating with ion bombardment. It concludes by describing the design criteria and limitations of brazing.

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 discusses tubular products made from wrought carbon or alloy constructional steels, particularly pipe, specialty tubing, and oil country tubular goods. The article covers product classifications, available specifications, chemical compositions, sizes, and other dimensional attributes. Some of the common types of pipe are standard pipe, conduit pipe, piling pipe, pipe for nipples, transmission or line pipe, water main and water well pipe, and pressure pipe. Pipe in suitable sizes and most products classified as tubing, both seamless and welded, may be cold finished. Pressure tubes, a separate classification, include double-wall brazed tubing, structural tubing, welded mechanical tubing, continuous-welded cold-finished mechanical tubing, and seamless mechanical tubing.

Cast irons primarily are iron alloys that contain more than 2% carbon and from 1 to 3% silicon. This article provides a description of iron-iron carbide-silicon system; and discusses the classification, composition, and characteristics of cast irons, such as gray, ductile, malleable, compacted graphite, and white cast iron. A table shows the correspondence between commercial and microstructural classification, as well as final processing stage in obtaining common cast irons.

Submerged arc welding (SAW) is suited for applications involving long, continuous welds. This article describes the operating principle, application, advantages, limitations, power source, equipment, and fluxes in SAW. It reviews three different types of electrodes manufactured for SAW: solid, cored, and strip. The article highlights the factors to be considered for controlling the welding process, including fit-up of work, travel speed, and flux depth. It also evaluates the defects that occur in SAW: lack of fusion, slag entrapment, solidification cracking, and hydrogen cracking. Finally, the article provides information on the safety measures to be followed in this process.

This article presents the binary eutectic phase diagram to understand the various structures that evolve in a binary eutectic system during solidification. It describes the various classifications and solidification principles of the eutectic structures. The formation of halos in eutectic microstructures of most alloy systems is also discussed.

Copper and copper alloys are widely used because of their excellent electrical and thermal conductivities, outstanding resistance to corrosion, and ease of fabrication, together with good strength and fatigue resistance. This article provides an overview of property and fabrication characteristics, markets, and applications of copper and its alloys. It contains several tables that provide helpful information on the chemical composition, classification, designation, uses, and mechanical properties of wrought copper and copper alloys.

Corrosion is classified into two categories: corrosion that is not influenced by any other process and corrosion that is influenced by another process such as the presence of stresses or erosion. This article discusses uniform corrosion, localized corrosion, metallurgically influenced corrosion, and microbiologically influenced corrosion, which fit under the classification of corrosion that is not influenced by any outside process. It also explains mechanically assisted degradation and environmentally induced cracking, which fit under the classification of corrosion that is influenced by an outside process.

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.