scholarly journals Effect of the Roll Surface Profile on Centerline Segregation in Soft Reduction Process

2012 ◽  
Vol 52 (7) ◽  
pp. 1266-1272 ◽  
Author(s):  
Chang Ho Moon ◽  
Kyung Shik Oh ◽  
Joo Dong Lee ◽  
Sung Jin Lee ◽  
Youngseog Lee
Keyword(s):  
Surface Profile ◽  
Reduction Process ◽  
Roll Surface ◽  
Centerline Segregation ◽  
Soft Reduction

Optimization of Soft Reduction Process for Continuous Thick Slab Casting

2014 ◽  
Vol 881-883 ◽  
pp. 1558-1561 ◽  
Author(s):  
Tao Han ◽  
Chang Gui Cheng ◽  
Jun Xue Mei ◽  
Jia Fa Zhu ◽  
Yan Jin
Keyword(s):  
Reduction Process ◽  
Transfer Model ◽  
Soft Reduction ◽  
Thick Slab ◽  
Central Segregation ◽  
Class B ◽  
Slab Casting ◽  
Distance Difference ◽  
Steady State Heat ◽  
Steady State Heat Transfer

In this paper, a two-dimensional non-steady-state heat transfer model has been established for the working conditions of thick slab in a steel plant in China, a modification has been made on the basis of the nailing experimental results, the slab solidification difference of practice and prediction by field heat tracing model has been analyzed. The results show that the actual solidification end point of slab is more close to meniscus than prediction, the distance difference is 0.592m, the better soft reduction zone is from 0.2 to 0.9, which the level of central segregation can be reduced from the class B 1.0 to C 1.0.

scholarly journals A new method for determination of the theoretical reduction amount for wide-thick slab during the mechanical reduction process

2021 ◽  
Vol 57 (1) ◽  
pp. 125-136
Author(s):  
C.-H. Wu ◽  
J.-H. Zeng ◽  
G.-R. Wu ◽  
X. Xie ◽  
M. Zhang
Keyword(s):  
Heat Transfer ◽  
Calculation Method ◽  
Infrared Camera ◽  
Reduction Process ◽  
Heat Transfer Model ◽  
Previous Method ◽  
Transfer Model ◽  
Slab Thickness ◽  
Soft Reduction ◽  
Thick Slab

Mechanical soft reduction (MSR) is an effective method for elimination of the centerline segregation and porosity of the continuous casting steel slab, and the reduction amount is a key parameter that determines whether the MSR could be applied successfully. In the present work, a 2D heat transfer model was developed for predicting the non-uniform solidification of the wide-thick slab. The measured shell thickness by nail shooting experiment and the measured slab surface temperature by infrared camera were applied to validate the 2D heat transfer model. A new calculation method of theoretical reduction amount that could consider the influence of non-uniform solidification of the wide-thick slab was then derived. Based on the predicted temperature field by the 2D heat transfer model and the newly-proposed calculation method, the required theoretical reduction amount and reduction gradient/rate for the wide-thick slab were calculated and discussed. The difference between the newly-proposed method and the previous method, the influence of the casting speed and slab thickness on the required theoretical reduction amount and reduction gradient/rate were also investigated.

Improvement of carbon segregation in cast bloom and heredity in hot-rolled bar

2021 ◽  
Vol 118 (6) ◽  
pp. 610
Author(s):  
Mengyun Zhang ◽  
Yanping Bao ◽  
Lihua Zhao ◽  
Xin Li
Keyword(s):  
Casting Speed ◽  
Reduction Process ◽  
Rolling Process ◽  
Solidification Structure ◽  
Soft Reduction ◽  
Carbon Segregation ◽  
The Core ◽  
Before And After ◽  
Core Areas ◽  
Hot Rolled

In this study, the effect of mechanical soft reduction on carbon segregation in the continuous casting of 300 × 400 mm 42CrMo alloy structural steel blooms was comparatively investigated by adjusting the casting speed, which was systematically optimized through numerical simulation. When the casting speed is 0.60 m · min−1, during the soft reduction process, the central solidification structure of the bloom becomes dense, and carbon segregation is improved. Moreover, the distribution of carbon in the samples before and after rolling was analyzed. Combined with the soft reduction process, the uniformity of carbon across the cross section of the bloom /bar distinctly improved for casting speeds of 0.50 m · min−1, 0.55 m · min−1 and 0.60 m · min−1, this was predominantly reflected in the core areas. The effective segregation length proportion of the bloom and rolled bar is approximately 40%. This phenomenon fully verifies the heredity characteristics of the elements in the rolling process.

scholarly journals Development of Soft Reduction Technology Using Crown Rolls for Improvement of Centerline Segregation of Continuously Cast Bloom

1994 ◽  
Vol 80 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Kohichi ISOBE ◽  
Hirobumi MAEDE ◽  
Kiyomi SYUKURI ◽  
Satoru SATOU ◽  
Takashi HORIE ◽  
...  
Keyword(s):  
Centerline Segregation ◽  
Soft Reduction ◽  
Continuously Cast

The Position Study of Heavy Reduction Process for Improving Centerline Segregation or Porosity With Extra-Thickness Slabs

2013 ◽  
Vol 85 (4) ◽  
pp. 645-658 ◽  
Author(s):  
Xinkai Zhao ◽  
Jiongming Zhang ◽  
Shaowu Lei ◽  
Yuanning Wang
Keyword(s):  
Reduction Process ◽  
Centerline Segregation

scholarly journals Control of Shrinkage Porosity and Spot Segregation in Ø195 mm Continuously Cast Round Bloom of Oil Pipe Steel by Soft Reduction

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Liang Li ◽  
Zhonghua Zhang ◽  
Ming Luo ◽  
Bo Li ◽  
Peng Lan ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Pipe Steel ◽  
Coupled Model ◽  
Reduction Process ◽  
Shrinkage Porosity ◽  
Soft Reduction ◽  
Sulfide Stress ◽  
Continuously Cast ◽  
Force Mode ◽  
Higher Temperature

Based on the Ø195 mm round bloom continuous casting of oil pipe steel, a two dimensional thermal-mechanical coupled model has been developed to investigate the deformation behavior of round bloom during soft reduction (SR) in the reduction force mode. Good agreement was achieved in surface temperature, shell thickness and contact zone width from modeling and measurement. Under the same reduction force, the reduction amount of round bloom at the front unit is much larger than back unit. Moreover, due to its higher temperature and lower center solid fraction, the deformation penetration before solidification is much stronger than that after solidification. Considering the limitation of the round bloom ovality, the maximum allowable force in reduction unit is calculated. According to the simulation results, a multi-unit soft reduction plan was proposed and carried out on the Ø195 mm round bloom. After the reduction process of No.1 to No.3 withdrawal units, the shrinkage porosity in the center of the round bloom was almost vanished, while the number and size of spot segregation were significantly reduced. Moreover, the oil pipe produced by the round bloom with SR got a better resistance to sulfide stress corrosion (SSC). It indicates that SR is an effective technology for the round bloom to control the shrinkage porosity and spot segregation in the continuous casting.

Application of the Dynamic Soft-Reduction Technology on the No.4 Slab Continuous Caster of Bayi Steel

2013 ◽  
Vol 652-654 ◽  
pp. 2441-2445
Author(s):  
Jian Feng Cao ◽  
Ke Feng ◽  
Zhi Wei Han
Keyword(s):  
Control Function ◽  
Continuous Caster ◽  
Reduction Process ◽  
Internal Quality ◽  
Internal Crack ◽  
Slab Caster ◽  
Soft Reduction ◽  
Reduction Function ◽  
Dynamic Soft Reduction ◽  
Slab Continuous Caster

The revamping & upgrading work has been done smoothly for the old soft-reduction system of the No.4 slab continuous caster in Bayi steel, as a result, all the segments (include both arc segments and level segments ) now have the dynamic soft-reduction function, which have been put into the industrial application successfully. Through the production practice, we can see that, after the revamping project, the dynamic soft-reduction function could be applied normally both in the arc segments and in the level segments for the No.4 slab caster, the whole soft-reduction process has been conducted steady and smoothly, the precision of roll gap control is good, the L2 model always makes an exact trace for the casting process and has the advanced algorithm, the L1 program has the reasonable control function and the reliable execution. When the soft-reduction action was executed in the unbending segment (Seg.7), there was no internal crack taking place for all the slabs, and the internal quality of slab such as center segregation was improved obviously, which had shown the metallurgical effect of the dynamic soft-reduction technology fully.

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