Double-Twist Torsion Testing to Assess Partial Recrystallization in Microalloyed Steels

The radiometric dating of calcrete is often problematical because impurities and open system conditions affect the apparent ages obtained. By applying both radiocarbon and uranium-series dating to calcrete in colluvium, it is shown that such conditions can be identified. In correlation with the stratigraphy, it is found that partial recrystallization severely decreases the radiocarbon ages of the upslope and shallower samples further down, whereas incorporation of limestone fragments from bedrock significantly increases the apparent ages of some of the uranium-series samples. It is concluded that the hillslope calcrete at the study site near Sede Beker in the Negev Desert, Israel, mainly developed shortly after 40 kyr ago, at a time when the Jordan Valley was being inundated to form the fossil Lake Lisan. Since their formation would have required higher rainfall than today, the results provide further evidence that the whole region was experiencing an increase in precipitation.

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Retraction Note To: Artificial neural network to predict the effect of heat treatments on Vickers microhardness of low-carbon Nb microalloyed steels

Neural Computing and Applications ◽

10.1007/s00521-020-05575-2 ◽

2021 ◽

Author(s):

Gholamreza Khalaj ◽

Hossein Yoozbashizadeh ◽

Alireza Khodabandeh ◽

Ali Nazari

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Vickers Microhardness ◽

Heat Treatments ◽

Microalloyed Steels ◽

Low Carbon ◽

Artificial Neural

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Microstructural Control in Thick-Walled Nb-Ti-V Microalloyed Linepipe Steels

Materials Science Forum ◽

10.4028/www.scientific.net/msf.467-470.223 ◽

2004 ◽

Vol 467-470 ◽

pp. 223-228

Author(s):

K.M. Banks

Keyword(s):

Grain Size ◽

Laboratory Simulation ◽

Microalloyed Steels ◽

Processing Parameter ◽

Strip Rolling ◽

Bearing Steels ◽

Simulation Results ◽

Linepipe Steels ◽

Ferrite Grain Size ◽

Microstructural Control

Various microstructure models for Nb-bearing steels were tested under industrial strip rolling conditions to establish a relationship between grain size and toughness in Ti-Nb-V microalloyed steels. For similar Nb contents, microstructure models for Nb steels were found to adequately describe recrystallisation kinetics in more complex Ti-Nb-V steels. For thick-walled linepipe (11.6mm), a minimum of 0.04%Nb is required to achieve adequate toughness. Retained strain was the dominant processing parameter factor affecting ferrite grain size. The predicted minimum amount of retained strain after the last pass required for sufficient grain refinement concurred with laboratory simulation results. For the rolling schedules investigated, metadynamic recrystallisation was predicted to occur during roughing, whilst static recrystallisation was predominant during finishing.

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