• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 춘계학술대회 논문집
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• pp.123-123
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• 2015

0.087 wt.% Gd-lean duplex stainless steels were inert arc-melted and cast in a mold. The micro-hardnesses of the rolling, transverse, short transverse directions were 258.5, 292.3, 314.7 HV, respectively. The 33% cold rolled specimen had the crystallographic texture that mainly (100) pole was concentrated to normal direction and (110) pole was concentrated in the center of normal and rolling directions. The corrosion potential and corrosion rate in artificial sea water were in the range of $105.6-221.6mV_{SHE}$, $0.59-1.06mA/cm^2$, respectively. The friction coefficient and wear loss of the 0.087 wt.% Gd-lean duplex stainless steels in artificial sea water were about 67% and 65% lower than in air, whereas, the wear efficiency was 22% higher. The corrosion and wear behaviors of the 0.087 wt.% Gd-lean duplex stainless steels significantly depended on the gadolinium phases.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.164-168
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• 2016

Lean duplex stainless steels with 0.087 wt.% gadolinium (Gd) were inert arc-melted and cast in molds of size $10mm{\times}10mm{\times}20mm$. The micro-hardnesses of the rolling direction (RD), transverse direction (TD) and short transverse (ST) direction were $258.5H_V$, $292.3H_V$, and $314.7H_V$, respectively. A 33% cold rolled specimen had the crystallographic texture that (100) pole was mainly concentrated to the normal direction (ND) and (110) pole was concentrated in the center of ND and RD. The corrosion potential and corrosion rate in artificial seawater and $0.1M\;H_2SO_4$ solution were in the range of $105.6-221.6mV_{SHE}$, $0.59-1.06mA/cm^2$, and $4.75-8.25mV_{SHE}$, $0.69-1.68mA/cm^2$, respectively. The friction coefficient and wear loss of the 0.087 w/o Gd-lean duplex stainless steels in artificial seawater were about 67% and 65% lower than in air, whereas the wear efficiency was 22% higher. The corrosion and wear behaviors of the 0.087 w/o Gd-lean duplex stainless steels significantly depended on the Gd phases.

• Nuclear Engineering and Technology
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• 제45권5호
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• pp.689-694
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• 2013

A duplex stainless steel sheet with 1 wt.% gadolinium was fabricated for a neutron absorbing material with high strength, excellent corrosion resistance, and low cost as well as high neutron absorption capability. The microstructure of the as-cast specimen has typical duplex phases including 31% ferrite and 69% austenite. Main alloy elements like chromium (Cr), nickel (Ni), and gadolinium (Gd) are relatively uniformly distributed in the matrix. Gadolinium rich precipitates were present in the grains and at the grain boundaries. The solution treatment at $1070^{\circ}$ for 50 minutes followed by the hot-rolling above $950^{\circ}$ after keeping the sheet at $1200^{\circ}$ for 1.5 hours are important points of the optimum condition to produce a 6 mm-thick plate without cracking.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1887-1892
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• 2021

The effect of gadolinium and boron on the texture development and magnetic properties of the texture controlled 23Cr-10NiCu duplex stainless steels were studied to develop a high performance neutron and electromagnetic shielding material. The 23Cr-10NiCu base alloy is composed of 60% of austenite and 40% of ferrite, whereas, the 23Cr-10NiCu-0.5Gd-0.8B modified alloy is composed of 66% of austenite, 27% of ferrite and 7% of CrFeB intermetallic compounds. The gadolinium and boron addition to the 23Cr-10NiCu base alloy increased mechanical properties. Microstructure observation showed that the small addition of 0.5 wt% gadolinium and 0.8 wt% boron to the alloy retarded to form texture at the same hot rolling conditions, and improved the maximum magnetism, residual magnetism and coercive force about 3%, 122% and 120%, respectively.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2014년도 추계학술대회 논문집
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• pp.212-212
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• 2014

0.04% Gd-duplex stainless steels (Gd-DSTSs) for neutron absorbing materials were inert arc-melted and poured into a Y-shape block with the size of $100{\times}100{\times}20[mm]$. The Gd-DSTS was hot rolled at $1200^{\circ}C$ followed by cold rolling to have 33% reduction. The average grain sizes of the rolling (RD), transverse (TD) and short transverse (ST) directions were 6, 7, $11{\mu}m$, respectively. The micro-hardnesses of the RD, TD and ST directions were 258.5, 292.3, 314.7 $H_V$, respectively. Corrosion potential and corrosion rate of the cold rolled Gd-duplex stainless steel in aerated artificial sea water and 0.1M $H_2SO_4$ solution were $0.2216V_{SHE}$, $0.0106A/cm^2$, $-0.0825V_{SHE}$, $0.0168A/cm^2$ for RD, $0.2210V_{SHE}$, $0.0077A/cm^2$, $0.0817V_{SHE}$, $0.0092A/cm^2$ for TD, $0.1056V_{SHE}$, $0.0059A/cm^2$, $0.0475V_{SHE}$, $0.0069A/cm^2$ for ST, respectively. The corrosion behavior depended on the texture, which were due to mainly grain boundary and minorly crystallographic texture. Friction coefficient and wear resistance were 2.07 and 0.48 mm, respectively.