scholarly journals Semi-Automatic Optimization of Steel Heat Treatments for Achieving Desired Microstructure

Author(s):  
Aarne Pohjonen ◽  
Vahid Javaheri ◽  
Joni Paananen ◽  
Juha Pyykkönen
2017 ◽  
Vol 114 ◽  
pp. 163-169
Author(s):  
Edimilson Zambaldi ◽  
Ricardo R. Magalhães ◽  
Bruno H.G. Barbosa ◽  
Sandro P. da Silva ◽  
Danton D. Ferreira

Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.


Author(s):  
A. W. West

The influence of the filament microstructure on the critical current density values, Jc, of Nb-Ti multifilamentary superconducting composites has been well documented. However the development of these microstructures during composite processing is still under investigation.During manufacture, the multifilamentary composite is given several heat treatments interspersed in the wire-drawing schedule. Typically, these heat treatments are for 5 to 80 hours at temperatures between 523 and 573K. A short heat treatment of approximately 3 hours at 573K is usually given to the wire at final size. Originally this heat treatment was given to soften the copper matrix, but recent work has shown that it can markedly change both the Jc value and microstructure of the composite.


Author(s):  
P. J. Lee ◽  
D. C. Larbalestier

Several features of the metallurgy of superconducting composites of Nb-Ti in a Cu matrix are of interest. The cold drawing strains are generally of order 8-10, producing a very fine grain structure of diameter 30-50 nm. Heat treatments of as little as 3 hours at 300 C (∼ 0.27 TM) produce a thin (1-3 nm) Ti-rich grain boundary film, the precipitate later growing out at triple points to 50-100 nm dia. Further plastic deformation of these larger a-Ti precipitates by strains of 3-4 produces an elongated ribbon morphology (of order 3 x 50 nm in transverse section) and it is the thickness and separation of these precipitates which are believed to control the superconducting properties. The present paper describes initial attempts to put our understanding of the metallurgy of these heavily cold-worked composites on a quantitative basis. The composite studied was fabricated in our own laboratory, using six intermediate heat treatments. This process enabled very high critical current density (Jc) values to be obtained. Samples were cut from the composite at many processing stages and a report of the structure of a number of these samples is made here.


2008 ◽  
Vol 128 (4) ◽  
pp. 289-297 ◽  
Author(s):  
Tsutomu Mizuno ◽  
Shigemi Enoki ◽  
Takashi Asahina ◽  
Takayuki Suzuki ◽  
Hiroyuki Maeda ◽  
...  

2014 ◽  
Vol 8 (3) ◽  
pp. 599 ◽  
Author(s):  
Paulo Henrique Dias dos Santos ◽  
Larissa Krambeck ◽  
Diogo Luiz Figueiredo dos Santos ◽  
Thiago Antonini Alves

Author(s):  
Ricardo Alexandre Amar de Aguiar ◽  
Pedro Manuel Calas Lopes Pacheco ◽  
Brenno Tavares Duarte

Alloy Digest ◽  
1958 ◽  
Vol 7 (7) ◽  

Abstract ELASTUF 44 is a special analysis, electric furnace chromium, nickel, molybdenum alloy steel heat treated to Rockwell C42-46, and machinable. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating and machining. Filing Code: SA-72. Producer or source: Brown-Wales Company.


Sign in / Sign up

Export Citation Format

Share Document