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API TR 21TR1-2019 pdf free download

API TR 21TR1-2019 pdf free download.Materials Selection for Bolting.
1 Scope This document provides guidance for the selection of materials and manufacturing processes for low-alloy steel bolting manufactured in accordance with API Specifcation 20E and nickel-based and stainless alloys manufactured in accordance with API Specifcation 20F. Table 2 and Table 3 are provided as guidance for the material selection of fasteners. 2 Normative References There are no referenced documents that are indispensable for the application of this document. 3? Terms,? Defnitions,? Acronyms,? Abbreviations,? and? Symbols 3.1? Terms? and? Defnitions 3.1.1 aging A thermal cycle that usually follows solution annealing in precipitation hardening materials. NOTE Aging can be performed at different temperatures and times to strengthen precipitation hardening materials, such as some stainless steel grades and nickel-based alloys. 3.1.2 annealing A thermal cycle involving heating and holding material at or above its solutionizing temperature, and then cooling at a slow rate, for such purposes as reducing hardness, improving machinability, facilitating cold working, producing a desired microstructure, or obtaining desired mechanical or other properties. 3.1.3 austenitize, quench, and temper A heat treatment process commonly associated with steels that strengthens by martensitic transformation, then restores toughness. NOTE The process consists of heating the material to its solutionizing temperature and holding, followed by rapid cooling (commonly in water, polymer, or oil media). When martensitic structure is obtained, the material is very strong, but extremely brittle. The tempering process reduces stresses and changes the microstructure to tempered martensite, which gives a very desirable combination of high strength and toughness. 3.1.4 banding The microstructural manifestation of segregated alloy elements. 3.1.7 case hardening One or more processes of hardening steel in which the outer portion, or case, is made substantially harder than the inner portion, or core. NOTE Most of the processes involve either enriching the surface layer with carbon, nitrogen, or boron, usually followed by quenching and tempering, or the selective hardening of the surface layer by means of fame or induction hardening. 3.1.8 cold working The process of deforming metal to a desired shape at a temperature below its recrystallization temperature. 3.1.9 cooling rates The time it takes steel to solidify from the molten state to solid state. 3.1.10 corrosion (general mass loss) Temperature plus the presence of water on the steel surfaces (aqueous phase) and oxygen to drive the reaction producing iron oxide (Fe 2 O 3 or Fe 3 O 4 ). 3.1.11 creep The tendency of metal to deform slowly and permanently under the infuence of mechanical stresses. It can occur as a result of continuous exposure to high levels of stress that are still below the yield strength of the material. NOTE Creep is pronounced in materials that are subjected to heat and stress for extended periods. Creep generally increases as the materials near their melting point. 3.1.12 dies Tools used in manufacturing to shape by cutting or pressing the raw material. 3.1.13 fatigue Progressive cracking or crack growth that occurs at some existing defect in the metal at a point of high stress (such as a notch), and grows in length over time with subsequent loading and unloading. 3.1.14 galling A severe form of adhesion wear that results in the transfer of metal from one part to the mating part. 3.1.15 hardness A unit of measure related to the resistance to plastic deformation from indentation. 3.1.16 hot working The process of deforming metal to a desired shape after the metal has been heated above its recrystallization temperature.
3.1.17 hydrogen? embrittlement HE A permanent loss of ductility in a metal caused by hydrogen with or without stress. 3.1.18 immersion zone A region where a component or assembly would remain continuously submerged in seawater. 3.1.19 marine atmosphere Located above the water level and above tidal and wave action. 3.1.20 marine fouling The accumulation of aquatic organisms, such as microorganisms, plants, and animals, on surfaces and structures immersed in or exposed to the aquatic environment [1] . 3.1.21 mud zone The region at the bottom of a body of marine saltwater that includes a sediment layer and some of the sublayers. 3.1.22 normalizing A thermal cycle involving heating to and holding at a solutionizing temperature, then cooling in air, to produce material uniformity resulting in improved machinability, strength, and toughness. NOTE This process is often used in combination with quench and temper.

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