ZHANG Jie
,
CAI Qing-wu
,
WU Hui-bin
,
ZHANG Kun
,
WU Bo
钢铁研究学报(英文版)
A new kind of Mn-Mo-Nb-Cu-B bainite steel which satisfied mechanical demands of E690 offshore plate steel was designed. The effect of two processes——thermomechanical control process (TMCP)+tempering (T) and thermomechanical control process (TMCP)+reheating and quenching (RQ)+tempering (T)——on microstructure and mechanical properties were studied by means of scan electron microscope (SEM), transmission electron microscope (TEM) and electron back scatter diffraction (EBSD). The results showed that optimal mechanical properties were available when tempering at 550 ℃ for both processes. The microstructure of the TMCP+T treated sample tempering in the range of 450 to 550 ℃ for 1 h did not change dramatically yet the lath in the TMCP+RQ+T treated sample merged together and transformed into polygonal ferrite. At the same time, the sub-structure of grain bainite transformed from lath to cell-shape to refine grains with tempering temperature mounting. Lots of sub-grain boundaries were located within bainite and adjacent bainite grain boundaries were high angle.
关键词:
offshore plate
,
low carbon bainitic steel
,
tempering
,
toughness
,
EBSD
YANG Guang-hui
,
CAO Jian-guo
,
ZHANG Jie
,
SONG Ping
,
YAN Tan-li
,
RAO Ke-feng
钢铁研究学报(英文版)
In order to solve the difficult profile and flatness control problem of wide non-oriented electrical steel sheets, the factors such as the relationship between strip crown control and strip width, the relationship between the maximum wearing value of work roll and the number of a rolling campaign and the wear contour change of work roll were analyzed on the basis of industrial test. Through analyzing the rolling process characteristics of non-oriented electrical steel sheets, the ASR (asymmetry self-compensating work rolls) shape control technology and its roll shifting strategy of the wider non-oriented electrical steel sheets was proposed and developed. When the technology was applied, the number of the wide non-oriented electrical steel (23 mm×1280 mm) in one rolling campaign rose from 40 coils of the trial production to 70 coils of the industrial production, the ratio of the measured strip crown less than 45 μm was increased from 500% to 949%, and the ratio of the measured strip crown more than 60 μm was decreased from 200% to 07%.
关键词:
silicon steel
,
shape control
,
hot rolling
,
roll contour
TIAN Li-li
,
Paolo Patrizi Jie
,
ZHANG Jie
钢铁研究学报(英文版)
In this paper we propose a new theoretical thermo-mechanical explanation of the uneven transverse temperature distribution, along the width, for thin and wide hot rolled produced strip. In particular, we base our reasoning starting from the irregular pressure/friction distribution, that lead to an uneven heat generation. A 2-D mathematical model to calculate the transverse temperature distribution is presented, both to give a physical explanation to our problem, and to be used as an essential basis to build a correspondent FEM simulation model, in which heat loss and generation are both considered. Deformation and friction heat are both described in details, having a paramount importance in our reasoning. The heat generation problem is split into two parts, for a clearer and more logical analysis: one for the strip centre, and one for the sides, in correspondence of the temperature peak points at 100mm from the strip edge. Finally it is shown how our new theoretical model can lead to the exact interpretation of the measured uneven temperature distribution.
关键词:
Hot strip rolling;Strip temperature distribution;Strip thermo-mechanical behaviour;Deformation heat;Friction heat
