Metallurgical Tempers

The tempers of age hardenable alloys are all designated by the letter T, followed by one to five digits, the precise definition of which can be found in standard EN 515. The most common tempers are listed in Table A.3.15. As with H tempers for strain hardenable alloys, the minimum mechanical properties can be standardised. 

Temper Solution heat treatment in furnace Controlled stretching Strain hardening Natural ageing Normal artificial ageing Over-aging Extrusions 

The most important European Standards on aluminium, which were published at the end of 1997, can be found in Table A.3.11. 

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Unalloyed aluminium is an excellent heat conductor, with roughly 60% of the thermal conductivity of copper, the optimum performer among common metals. The thermal conductivity of aluminium alloys depends on their composition and metallurgical temper (Tables A.3.5 and A.3.9). 

The same applies to metallurgical tempers. A strain-hardened temper (temper HIX) will not have the same deformation capacity as a soft temper (temper O) in strain-hardenable alloys, and as an aged temper (temper T4) in age-hardenable alloys. Industrial alloys comprise... 

In European standardisation, casting alloys are designated by five figures, followed by the metallurgical temper designation, such as 42100 T6 (formerly designated as A-S7G03 Y23). 

Table A.3.15. Definition of metallurgical tempers according to the standard EN 515...

As in my first book, I have chosen a practical and realistic approach to the corrosion of aluminium a practitioner s approach. The corrosion resistance of an alloy depends not only on its chemical composition and metallurgical temper, but also on the joining method and the conditions of service. 

Ferrophosphoms is produced as a by-product in the electrothermal manufacture of elemental phosphoms, in which iron is present as an impurity in the phosphate rock raw material. The commercial product contains ca 23—29% P and is composed primarily of Fe2P [1310-43-6] and Fe P [12023-53-9] along with impurities such as Cr and V. Ferrophosphoms is used in metallurgical processes for the addition of phosphoms content. Low concentrations (up to - 0.1%) of phosphoms in wrought and cast iron and steel not only increases the strength, hardness, and wear resistance but also improves the flow properties. In large stmctural members and plates, it is desirable to use a type of steel that does not need to be quenched or tempered, and thus does not exhibit weld-hardening. This property is afforded by the incorporation of a small quantity of phosphoms in steel. Ferrophosphoms from western U.S. phosphoms production is used as a raw material for the recovery of vanadium (see Vanadiumand vanadiumalloys). 

It was noted in McCance s obituary of Desch that Desch did not find it easy to work with Professor Huntington who was quick tempered and exacting. 45(a) Macadam undertook accurate analysis of metal samples, which were then examined metallo-graphically by Desch. In January 1909, Macadam and Desch were married. McCance quotes Huntington that Cecil Desch had robbed him of his best assistant. 45(a) The Desch family moved shortly afterwards to Glasgow, where Desch had been appointed as Lecturer in metallurgical chemistry. Macadam had two daughters, and the only other reference to her was at a later appointment of Desch at the University of Sheffield, that ... 

The author discusses selected examples of Auger electron spectroscopy applications to the study of the role played by sulfur adsorption in the field of heterogeneous catalysis and its implication for the metallurgical problems of segregation, surface self-diffusion and temper embrittlement. 

In most applications, the decision has been to use the steel m a normalized and tempered rather than a quenched and tempered condition of heat treatment. Furthermore, to keep certain metallurgical factors within tolerable limits, the following supplemental requirements were considered necessary ... 

K scc depends on metallurgical factors (it usually decreases as the strength of the steel increases, even though it also depends on the microstructure of the material, e. g. it is lower in quenched and tempered steel than in cold-worked steels) and on environmental factors (for instance, in alkaline environments and in the absence of chlorides, Kfscc so high that normal mechanical failure takes place before stress corrosion cracks can develop). 

With all due respect to the metallurgical characteristics, temper, thickness, or material shape, over which the slitter has no control, the quality of the slit strand is still a function of its edge condition, accuracy of width, flatness or crosscurvature, camber, and surface finish. 

The UNS designations for cast copper alloys consist of numbers C80000 through C99999. Temper designations that define metallurgical condition, heat treatment, and/or casting method further describe the alloy. 

METALLURGICAL FACTORS. Typical metallurgical factors influencing ductile—brittle behavior are temper, microstructure, and welds. In general, the stronger the condition of a given alloy, the more susceptible it becomes to brittle behavior. As strength increases, ductility decreases. There are some exceptions... 

Loop No. 10, which was normalized from 954°C and tempered at 732°C after welding, stood up poorly when compared with other tests. The heat-treating was done in an argon atmosphere, and no subsequent alteration was made to the surface left by the heat treatment. This heat treatment was thought, from some observations in the pumped loops, to improve corrosion resi,stance. It is believed that the poor results of test No. 10 are due to alteration of the surface during the heat treatment and not to the metallurgical structure of the steel. Loops No. 11 and 12 had Be and graphite inserts in the hot leg to study their effect on mass tramsfer and also the stability of U, Mg, and Zr concentrations. No detrimental effects on either have been observed. 

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