Search Results for high-purity iron

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 article discusses the ferromagnetic properties of soft magnetic materials, explaining the effects of impurities, alloying elements, heat treatment, grain size, and grain orientation on soft magnetic materials. It describes the types of soft magnetic materials, which include high-purity iron, low-carbon irons, silicon (electrical) steels, nickel-iron alloys, iron-cobalt alloys, ferritic stainless steels, amorphous metals, and ferrites (ceramics). Finally, the article provides a short note on alloys for magnetic temperature compensation.

This article briefly reviews the production methods and characteristics of plain carbon and low-alloy water-atomized iron and steel powders, high-porosity iron powder, carbonyl iron powder, and electrolytic iron powder. It emphasizes on atomized powders, because they are the most widely used materials for ferrous powder metallurgy. The article provides information on the properties and applications of these powders. It also includes an overview of diffusion alloying, basics of admixing, and bonded premixes.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of pure irons and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the grain-boundary cavitation; slip lines; intergranular fracture; cleavage fracture; notch-impact fracture; oxide inclusions and blowholes; ductile rupture; impact fracture and tensile-test fracture surfaces; fatigue striations; and crack initiation and propagation of pure irons.

Materials of construction for equipment and piping in pharmaceutical processing plants must be resistant to corrosion from the high-purity water, the buffer solutions used in preparation of the products, and the cleaning solutions used to maintain the purity of the product. The primary water used in pharmaceutical production is water for injection (WFI). This article presents the steps for preparing WFI and discusses the effect of chlorides on stainless steel. It provides information on the passive layer of stainless steels and chromium-containing nickel alloys. The article provides information on the surface finish of pharmaceutical equipment. It discusses the classification of rouge and the characteristics of cast type 316L stainless steel. The article also explains how and when to perform cleaning and repassivation process on classes of rouge.

Powder metallurgy (PM) techniques are effective in making magnetically soft components for use in magnetic part applications. This article provides an account of the factors affecting magnetism, permeability, and hysteresis losses. It includes information on the magnetic properties of PM materials that are used in the magnetic part applications, namely, pure iron, phosphorus irons, ferritic stainless steels, 50 nickel-50 iron, and silicon irons. The article describes the factors that affect and optimize magnetic properties. It contains a table that lists the magnetic properties possible in metal injection molding parts. The article also discusses ferromagnetic cores used in alternating current applications and some permanent magnets, such as rare earth-cobalt magnets and neodymium-iron-boron (neo) magnets.

This article provides a discussion on the process descriptions, processing conditions, and processing variables of the most common chemical methods for metal powder production. These methods include oxide reduction, precipitation from solution, and thermal decomposition. Methods such as precipitation from salt solution and gas, chemical embrittlement, hydride decomposition, and thermite reactions are also discussed. The article also discusses the methods used to produce powders electrolytically and the types of metal powders produced. The physical and chemical characteristics of these powders are also reviewed.

This article examines the embrittlement of iron and carbon steels. It describes compositional, processing, and service conditions that contribute to the problem and presents examples of how embrittlement influences mechanical properties. Embrittlement due to hydrogen is the most common form of embrittlement and influences the behavior and properties of nearly all ferrous alloys and many metals. The article explains why hydrogen embrittlement is so widespread and reviews the many types of damage it can cause. It also explores other forms of embrittlement, including metal-induced embrittlement, strain-age and aluminum nitride embrittlement, thermal embrittlement, quench cracking, 475 deg C and sigma phase embrittlement (in FeCr alloys), temper embrittlement, and embrittlement caused by neutron irradiation. In addition, the article covers stress-corrosion cracking along with properties and conditions that affect it, and the procedures to detect and evaluate it.

Particle image analysis of metal powders can be easily performed with optical macroscopes and microscopes. This article provides examples of the particle image analysis on powders used in the powder metallurgy industry.

This article begins with a discussion on the corrosion characteristics of unalloyed magnesium and two major magnesium alloy systems. It shows the effects of iron and 13 other elements on the saltwater corrosion performance of magnesium in binary alloys with increasing levels of the individual elements. The article illustrates the effect of increasing iron, nickel, and copper contamination on the standard ASTM B 117 salt-spray performance of the die-cast AZ91 test specimens as compared to the range of performance observed for cold-rolled steel and die-cast aluminum alloy 380 samples. It discusses the effect of heat treating and cold working on the corrosion rates of the die-cast AZ91 alloy. The article concludes with a description on the causes of corrosion failures in magnesium alloys.