Effects of hot top pulsed magneto-oscillation on solidification structure of steel ingot

The chemical heterogeneities of alloying elements were evaluated in the hot top plus the top of a 40-ton ingot of as-cast high strength low alloy steel. The chemical compositions of small samples, taken from a slice cut along the longitudinal axis of the ingot, were obtained using mass spectroscopy. The chemical results were used to construct the chemical heterogeneity maps of C, Mn, Ni, Cr and Mo in the entire slice. The analyses of the different maps indicate the existence of positive segregation for all segregated elements except Ni where no segregation was observed. The most important macrosegregation was revealed in the centerline of the ingot. Carbon presents the highest degree of segregation whereas Mo presents the lowest one. In term of homogeneity degrees, Mn, Ni, Cr and Mo present better homogeneity than C whether in the top of the ingot or in the hot top.

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Effect of Surface Active Element on the Initial Solidification Structure of Stainless Steel Ingot

Tetsu-to-Hagane ◽

10.2355/tetsutohagane1955.75.8_1308 ◽

1989 ◽

Vol 75 (8) ◽

pp. 1308-1315 ◽

Cited By ~ 2

Author(s):

Hideo MIZUKAMI ◽

Yutaka NAGAKURA ◽

Takaji KUSAKAWA

Keyword(s):

Stainless Steel ◽

Active Element ◽

Steel Ingot ◽

Solidification Structure ◽

Surface Active Element ◽

Surface Active ◽

Initial Solidification ◽

Effect Of Surface

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On the Quantitative Observation of Solidification Structure and Segregation in Steel Ingot by the Autoradiographic Method

Tetsu-to-Hagane ◽

10.2355/tetsutohagane1955.55.13_1199 ◽

1969 ◽

Vol 55 (13) ◽

pp. 1199-1211 ◽

Cited By ~ 3

Author(s):

Kiichi NARITA ◽

Masayuki TANIGUCHI

Keyword(s):

Steel Ingot ◽

Solidification Structure ◽

Autoradiographic Method

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Quality of a ball-bearing-steel ingot cast in an ingot mold without a hot top

Metallurgist ◽

10.1007/bf00733248 ◽

1981 ◽

Vol 25 (8) ◽

pp. 307-309

Author(s):

V. M. Borevskii ◽

V. I. Starykh ◽

V. V. Burtsev ◽

B. P. Krikonov ◽

I. L. Shturgunov ◽

...

Keyword(s):

Ingot Mold ◽

Ball Bearing ◽

Steel Ingot ◽

Bearing Steel ◽

Hot Top ◽

Ingot Cast ◽

Ball Bearing Steel

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Numerical simulation of solidification structure of 6.5 wt-%Si steel ingot slab

Ironmaking & Steelmaking ◽

10.1179/1743281215y.0000000011 ◽

2015 ◽

Vol 42 (9) ◽

pp. 656-663 ◽

Cited By ~ 6

Author(s):

W. Song ◽

J. M. Zhang ◽

Y. Liu ◽

S. X. Wang ◽

B. Wang

Keyword(s):

Numerical Simulation ◽

Steel Ingot ◽

Solidification Structure

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Effects of Low Frequency Electromagnetic Field on the Solidification Structure of 6063 Aluminum Alloy during Hot-Top Casting

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.857 ◽

2011 ◽

Vol 675-677 ◽

pp. 857-860

Author(s):

Xiang Jie Wang ◽

Jian Zhong Cui ◽

Qing Feng Zhu

Keyword(s):

Electromagnetic Field ◽

Aluminum Alloy ◽

Low Frequency ◽

Casting Process ◽

Liquid Pool ◽

Solidification Structure ◽

Cooling Curves ◽

Melt Temperature ◽

Hot Top ◽

6063 Aluminum Alloy

Low frequency electromagnetic (LFE) field was applied during the conventional hot-top casting process. Thermocouples were used to measure the cooling curves from the border to the center of the ingot during steady-state of casting process, cooling curves were obtained, and effects of low frequency electromagnetic field on the solidification, macrostructure during the conventional hot-top casting for 6063 aluminum alloy process were analyzed. The experimental results show that the forced convection caused by the low frequency electromagnetic (LFE) filed can make the melt temperature uniform, promote the evacuation of superheat, make the temperature in the liquid pool lower than the liquidus temperature of 6063 aluminum alloy, increase the number of floating nuclei, make the ingot with fine and homogeneous macrostructure, though there is no addition of any grain refiners.

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Vacuum Arc Remelting Process of High-Alloy Bearing Steel and Multi-Scale Control of Solidification Structure

Materials Science Forum ◽

10.4028/www.scientific.net/msf.817.826 ◽

2015 ◽

Vol 817 ◽

pp. 826-836

Author(s):

Yuan Sheng Huang ◽

Mao Sheng Yang ◽

Jing She Li ◽

Li Guo Bai

Keyword(s):

Molten Pool ◽

Moving Boundary ◽

Steel Ingot ◽

Primary Dendrite ◽

Bearing Steel ◽

Solidification Structure ◽

Vacuum Arc ◽

High Alloy ◽

Pool Shape ◽

Vacuum Arc Remelting

Utilizing Pro-cast software, the whole vacuum arc remelting process of high-alloy bearing steel ingot (the diameter was 160 mm and the high was 600 mm) was simulated. And moving face quality and moving boundary conditions were added to the simulation. Purposes of the simulation were to explore the influence of smelting powers on the temperature field, pool shape and solidification microstructure in vacuum arc remelting process. The depth of molten bath gradually increased and stabilized finally and the pool shape transferred from flat to funnel. When smelting power increased, the depth of molten pool became deeper and the width of mushy zone slightly reduced; the size of primary dendrite and secondary dendrite spacing increased significantly; the percentage and size of columnar crystals also increased. A reasonable power-time cure was given to guide industrial melting after simulation, the size of molten pool morphology and microstructure were controlled in an ideal range under the reasonable cure. The simulated grain morphology agreed well with the experimental pickling result.

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Microstructure and Crystallographic Texture of Laser Additive Manufactured Nickel-Based Superalloys with Different Scanning Strategies

Crystals ◽

10.3390/cryst11060591 ◽

2021 ◽

Vol 11 (6) ◽

pp. 591

Author(s):

Xingbo Liu ◽

Hui Xiao ◽

Wenjia Xiao ◽

Lijun Song

Keyword(s):

Additive Manufacturing ◽

Epitaxial Growth ◽

Crystallographic Texture ◽

Continuous Wave ◽

Flow Direction ◽

Fiber Texture ◽

Laves Phase ◽

Solidification Structure ◽

Columnar Grains ◽

Scanning Strategies

Control of solidification structure and crystallographic texture during metal additive manufacturing is a challenging work which attracts the increasing interest of researchers. In the present work, two kinds of scanning strategies (i.e., single-directional scanning (SDS) and cross-directional scanning (CDS) were used to control the solidification structure and crystallographic texture during quasi-continuous-wave laser additive manufacturing (QCW-LAM) of Inconel 718. The results show that the solidification structure and texture are strongly dependent on scanning strategies. The SDS develops a typical fiber texture with unidirectional columnar grains, whereas the CDS develops a more random texture with a mixture of unidirectional and multidirectional grains. In addition, the SDS promotes the continuously epitaxial growth of columnar dendrites and results in the linearly distributed Laves phase particles, while the CDS leads to the alternately distributed Laves phase particles with chain-like morphology and discrete morphology. The changed stacking features of molten-pool boundary and the switched heat flow direction caused by different scanning strategies plays a crucial role on the epitaxial growth of dendrites and the final solidification structure of the fabricated parts.

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Quantitative Correlation and Control Strategy for Element Content Fluctuation along Casting Direction in Central Area of Continuous Casting Billet

Metals ◽

10.3390/met11030452 ◽

2021 ◽

Vol 11 (3) ◽

pp. 452

Author(s):

Dongwei Guo ◽

Zibing Hou ◽

Zhiqiang Peng ◽

Qian Liu ◽

Jianghai Cao

Keyword(s):

Control Strategy ◽

Central Area ◽

Solidification Structure ◽

Equiaxed Crystal ◽

Correlation Relationship ◽

Zone Formation ◽

Zone Width ◽

Quantitative Correlation ◽

Central Segregation ◽

And Control

The statistical correlation was applied to analyze the specific and quantitative correlation relationship between the solidification structure and central segregation along the casting direction in carbon steel billet. On this basis, the segregation formation mechanism of the solute element and related control strategy were investigated. It is found that the equiaxed crystal zone fluctuation along the casting direction determines the fluctuation degree of central segregation. At the same time, the central segregation at a certain position is mostly affected by the equiaxed crystal zone width at the hysteretic position. Moreover, the casting speed can influence the columnar to equiaxed transition (CET) fluctuation along the casting direction by affecting the flow of molten steel in the billet. Overall, the segregation mechanism of solute elements along the casting direction can be summarized into two aspects: First, with the growth of columnar crystals in the initial stage, the segregated solutes are continuously enriched and distributed in the equiaxed crystal zone after CET. The fluctuation of the equiaxed crystal zone will affect the distribution of the enriched solute in the billet and cause the fluctuation of the central segregation. Second, due to the solidification shrinkage at the end of solidification, the solute-enriched liquid phase at the hysteretic position is pumped to the solidification endpoint and forms the central V-shaped segregation. Meanwhile, the stable solidification structure (columnar crystal length or equiaxed crystal zone width) along the casting direction and control measures preceded equiaxed crystal zone formation are beneficial to reduce the central V-shaped segregation.

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