Glossary |
Boiler and boiler tube industry terms and their definitions.
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| Hardenability | The property in steel that determines the depth and distribution of hardness induced by cooling from a suitable elevated temperature. The hardness can vary with the cooling rate. |
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| Hardness | "A measure of the degree of a materials resistance to indentation. It is usually determined by measuring resistance to penetration, by such tests as Brinell, Rockwell, and Vickers." |
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| Heat Treatment | A combination of heating and cooling operations applied to a metal or alloy in the solid state to obtain desired conditions or properties. Heating for the sole purpose of hot working is excluded from the meaning of this definition. See various types below. |
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| Heat Treatment - Age Hardening | "Age Hardening- Hardening by aging, usually after rapid cooling or cold working. Hardening is a result of a precipitation process, often submicroscopic, which occurs when a supersaturated solid solution is naturally aged at atmospheric temperature or artificially aged in some specific range of elevated temperature. Aging occurs more rapidly at higher temperatures. (Synonymous with precipitation hardening)" |
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| Heat Treatment - Air Hardening | Air Hardening- Heating a suitable grade of steel with high hardenability above the critical temperature range and then cooling in air for the purpose of hardening. |
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| Heat Treatment - Air Hardening | Air Hardening- Heating a suitable grade of steel with high hardenability above the critical temperature range and then cooling in air for the purpose of hardening. |
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| Heat Treatment - Air Hardening | Air Hardening- Heating a suitable grade of steel with high hardenability above the critical temperature range and then cooling in air for the purpose of hardening. |
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| Heat Treatment - Annealing | "Annealing- Annealing is a heat treatment process which usually involves a relatively slow cooling after holding the material for some time at the annealing temperature. The purpose of the annealing treatment may include the following: (a) to induce softness: (b) to remove internal stresses: (c) to refine the grain size: (d) to modify physical and/or mechanical properties: (e) to produce a definite microstructure: (f) to improve machinability. It is generally desirable to use more specific terms in describing the heat treatment to be used, e.g., finish anneal, full anneal, or medium anneal, as applicable." |
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| Heat Treatment - Bright Anneal | "Bright Anneal- Carried out in a controlled furnace atmosphere, so that surface oxidation is reduced to a minimum and the tube surface remains relatively bright." |
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| Heat Treatment - Dead Soft | Dead Soft- A heat treatment applied to achieve maximum softness and ductility |
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| Heat Treatment - Drawing | "Drawing- Synonymous with TEMPERING, which is preferable." |
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| Heat Treatment - Finish Anneal | "Finish Anneal- Heating of cold-worked tubing to a temperature below the lower critical, usually 950F. Generally this treatment will relieve peak stresses without altering hardness to any extent." |
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| Heat Treatment - Full Anneal | Full Anneal- Heating to a temperature above the upper critical and slow cooling below the lower critical. |
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| Heat Treatment - Isothermal | Isothermal Anneal- Austenitizing a heat treatable alloy and cooling to and holding within the range of temperature at which austenite transforms to a relatively soft ferrite-carbide aggregate. |
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| Heat Treatment - Medium Anneal | Medium Anneal- Subjecting tubing to a subcritical temperature to obtain specific mechanical properties. |
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| Heat Treatment - Normalize | Normalize- Normalizing is a process which consists of heating to a temperature approximately 100F above the upper critical temperature and cooling in still air. |
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| Heat Treatment - Quenching | "Quenching- A process of rapid cooling from an elevated temperature, by contact with liquids or gases." |
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| Heat Treatment - Soft Anneal | Soft Anneal- A high temperature stress relieving anneal usually preformed in the temperature range of 1250 to 1350F. This anneal reduces hardness and strength of a cold worked steel to achieve near maximum softness. |
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| Heat Treatment - Solution Anneal | "Solution Anneal- Heating steel into a temperature range wherein certain elements or compounds dissolve, followed by cooling at a rate sufficient to maintain these elements in solution at room temperature. The expression is normally applied to stainless and other special steels." |
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| Heat Treatment - Spheroidizing Anneal | Spheroidizing Anneal- A general term which refers to heat treatments that promote spheroidal or globular forms of carbide in carbon or alloy steels. |
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| Heat Treatment - Stabilizing Anneal | Stabilizing Anneal- A treatment applied to austenitic stainless steels wherein carbides of various forms are deliberately precipitated. Sufficient additional time is provided at the elevated temperature to diffuse chromium into the areas adjacent to the carbides (usually grain boundaries). This treatment is intended to lessen the chance of intergranular corrosion. |
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| Heat Treatment - Stress Relieving | "Stress Relieving- A heat treatment which reduces internal residual stresses that have been induced in metals by casting, quenching, welding, cold working, etc. The metal is soaked at a suitable temperature for a sufficient time to allow readjustment of stresses. The temperature of stress relieving is always below the transformation range. Finish anneal, medium anneal, and soft anneal (sub-critical) describe specific types of stress relief anneals." |
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| Heat Treatment - Tempering | Tempering- Reheating quenched or normalized steel to a temperature below the transformation range (lower critical) followed by any desired rate of cooling. |
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| Hot Finished Seamless Tubing | "Tubing produced by rotary piercing, extrusion, and other hot working processes without subsequent cold finishing operations." |
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| Hot Rolled ERW Tubing | "As welded electric resistance welded tubing made from hot rolled strip, sheet, or bands." |
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| Hot Shortness (Red Shortness) | A condition encountered in some metals wherein ductility is lessened at hot working temperatures. |
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| Hot Working | The mechanical working of metal above the recrystallization temperature. |
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| Huey Test | "A corrosion test for stainless steels. The weight loss per unit area is measured after each of five 48-hour boils in 65% nitric acid. The test results are calculated to and reported as the average corrosion rate of the five boils in inches per month (imp) corrosion rates. The test is used to determine the suitability of a material for nitric acid service. Since most of the weight loss is due to intergranular attack, the Huey test can be used as an indication of the resistance of a stainless steel to intergranular corrosion." |
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| Hydrostatic Test | "A test in which a liquid, usually water, under pressure, is used internally to detect and locate leaks in a tube of a fabricated structure." |
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