Numerical analysis of flow behaviour, grain size prediction and experimental verification of hot rolled ultralow carbon niobium microalloyed steel

2021 ◽  
Vol 52 (7) ◽  
pp. 725-738
Author(s):  
H. Khalifa ◽  
G.M. Megahed ◽  
T. El‐Bitar ◽  
M.A. Taha
Keyword(s):  
Grain Size ◽  
Numerical Analysis ◽  
Experimental Verification ◽  
Microalloyed Steel ◽  
Flow Behaviour ◽  
Niobium Microalloyed Steel ◽  
Hot Rolled ◽  
Ultralow Carbon

Critical Strain for Complete Austenite Recrystallisation during Rough Rolling of C-Mn Steel and Nb-Ti-V Microalloyed Steel

2018 ◽  
Vol 941 ◽  
pp. 46-51
Author(s):  
Dannis Rorisang Nkarapa Maubane ◽  
Charles Witness Siyasiya ◽  
Kevin Mark Banks ◽  
Waldo Edmund Stumpf
Keyword(s):  
Grain Size ◽  
Microalloyed Steel ◽  
Plain Carbon Steel ◽  
Rolled Plate ◽  
Austenite Grain Size ◽  
Nucleation Sites ◽  
First Pass ◽  
Industrial Heating ◽  
Hot Rolled ◽  
Softening Fraction

The influence of roughing strain on the extent of austenite recrystallisation in plain carbon steel and Nb-Ti-V microalloyed steel was investigated. Reheating and roughing simulations were conducted on a deformation dilatometer using industrial heating, soaking times, strain and strain rates. The roughing schedules comprised of varying the pass strain magnitude within a typical roughing temperature range. The double stroke method was used to determine the austenite softening fraction. The austenite grain size, prior to and after rolling, was measured on quenched specimens. Grain refinement was achieved in both steels after all rolling schedules. An applied pass strain of 0.15 was sufficient to completely soften the austenite after the first pass and produced the finest recrystallised grain size. This was attributed to sufficient nucleation sites and driving force for recrystallisation compared to lower strains. Partial recrystallisation occurred after the first pass due to the relatively coarse initial grain size. The steel chemistry played an insignificant role in controlling the recrystallisation kinetics at high roughing temperatures. The through-thickness strain distribution calculated from FEM simulations showed that, for a given applied strain, a similar magnitude of deformation is achieved at the centre of a hot-rolled plate.

Effect of Initial Austenite Microstructure on the Softening – Precipitation Interaction in a Low Nb Microalloyed Steel

2007 ◽  
Vol 550 ◽  
pp. 429-434 ◽  
Author(s):  
C. Iparraguirre ◽  
Ana Isabel Fernández-Calvo ◽  
Beatriz López
Keyword(s):  
Grain Size ◽  
Microalloyed Steel ◽  
Recovery Process ◽  
Precipitation Kinetics ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Nb Microalloyed Steel ◽  
Niobium Microalloyed Steel ◽  
Softening Fraction

The influence of initial grain size on the softening-precipitation interaction in a low niobium microalloyed steel has been investigated. The study has revealed that for the largest initial grain size (1000 μm), the recrystallised fraction remains lower than the softening fraction until relatively long times are reached. In contrast, for the smallest initial grain size (166 μm) both magnitudes are similar. As a result, precipitation interacts with recrystallisation in the case of the finest austenite grain size, whereas for the coarsest one, since recrystallisation is significantly retarded, interaction with recovery process is observed. Apparently, the initial austenite grain size does not affect precipitation kinetics.

Innovative Use of Profiled Steel Plates for Seismic Structural Performance

2005 ◽  
Vol 8 (3) ◽  
pp. 247-257 ◽  
Author(s):  
Y. Fukumoto ◽  
T. Takaku ◽  
T. Aoki ◽  
K. A. S. Susantha
Keyword(s):  
Numerical Analysis ◽  
Seismic Performance ◽  
Structural Design ◽  
Design Method ◽  
Steel Plates ◽  
Structural Performance ◽  
Cyclic Testing ◽  
Beam Columns ◽  
Bridge Bents ◽  
Hot Rolled

This paper presents the innovative use of hot-rolled thickness-tapered mill products, longitudinally profiled (LP) plates, for the seismic performance of bridge bents of single and portal framed piers. The study involves the inelastic cyclic testing and numerical analysis of tested beam-columns and portal frames in order to evaluate the effects of tapering ratios of LP plates, penetration of yielding, and number of locally buckled panels on their structural ductility. A structural design method is proposed for the portal frames having LP panels under cyclic loadings.

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