scholarly journals Microstructural Evolution And Mechanical Properties of FCAW Joints In 9% Ni Steel Prepared With Two Types of Ni-Based Weld Metals

2022 ◽  
Author(s):  
Jiyong Hwang ◽  
Kwangsu Choi ◽  
Sang Min Lee ◽  
Hyo Yun Jung
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Temperature Gradient ◽  
Weld Metal ◽  
Crystal Growth Rate ◽  
Inconel 625 ◽  
Large Temperature ◽  
Joint Interface ◽  
Weld Metals ◽  
Flux Cored Arc Welding

Abstract The microstructural and mechanical evaluation of 9% Ni steel with Flux-Cored Arc Welding was performed with two different Ni-based weld metals: Inconel 625 and Hastelloy 609. Weld metals showed the microstructural change depending on the temperature gradient and crystal growth rate for each region during the cooling after welding. At the bottom of the weld metal, which is rapidly cooled in contact with the cold base metal, a cellular/planar growth was exhibited due to a large temperature gradient and low crystal growth rate. While, columnar dendrites were exhibited in the central region cooled relatively slowly and precipitates were observed in the interdendritic region. In the low-temperature toughness test, the absorbed impact energies were 89 and 55 J for Inconel 625 and Hastelloy 609, respectively. When Inconel 625 is used as the weld metal compared to Hastelloy 609, the high content of the γ stabilizer and martensite start temperature decreasing elements leads to the formation of a thicker γ-phase layer and thinner martensite layer in the transition region. In addition, high content of these elements suppresses the martensite transformation and maintains the stability of the weld joint interface even at low temperatures, resulting in the higher absorbed impact energy.

scholarly journals Depth-hoar crystal growth in the surface layer under high temperature gradient

1993 ◽  
Vol 18 ◽  
pp. 39-45 ◽  
Author(s):  
Takuya Fukuzawa ◽  
Eizi Akitaya
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
High Temperature ◽  
Temperature Gradient ◽  
Crystal Growth Rate ◽  
Snow Surface ◽  
Night Time ◽  
High Temperature Gradient ◽  
Series Of Experiments ◽  
The Given

The quick growth of depth-hoar crystals was observed at night-time just below the snow surface on a south-facing slope. This growth was due to a high temperature gradient (> 100 K m−1) near the snow surface under clear skies after a thin deposition of new snow on older and denser snow. The temperature gradient was greater when internal melting had taken place during daytime, keeping the sub-surface snow temperature at 0°C even after sunset until all liquid water had frozen. To understand the relationship between the crystal growth rate and the temperature gradient, a series of experiments was carried out in the laboratory. The snow sample was set under a constant temperature gradient between 100 and 300 K m− and sustained for about 50 h. The average crystal size increased linearly with time and the crystal growth rate increased as the given temperature gradient increased. The growth rates were in the order of 10−9 m s−1, which gave a good agreement with the results of the field observation.

scholarly journals Depth-hoar crystal growth in the surface layer under high temperature gradient

1993 ◽  
Vol 18 ◽  
pp. 39-45 ◽  
Author(s):  
Takuya Fukuzawa ◽  
Eizi Akitaya
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
High Temperature ◽  
Temperature Gradient ◽  
Crystal Growth Rate ◽  
Snow Surface ◽  
Night Time ◽  
High Temperature Gradient ◽  
Series Of Experiments ◽  
The Given

The quick growth of depth-hoar crystals was observed at night-time just below the snow surface on a south-facing slope. This growth was due to a high temperature gradient (> 100 K m−1) near the snow surface under clear skies after a thin deposition of new snow on older and denser snow. The temperature gradient was greater when internal melting had taken place during daytime, keeping the sub-surface snow temperature at 0°C even after sunset until all liquid water had frozen. To understand the relationship between the crystal growth rate and the temperature gradient, a series of experiments was carried out in the laboratory. The snow sample was set under a constant temperature gradient between 100 and 300 K m− and sustained for about 50 h. The average crystal size increased linearly with time and the crystal growth rate increased as the given temperature gradient increased. The growth rates were in the order of 10−9 m s−1, which gave a good agreement with the results of the field observation.

TEMPERATURE DEPENDENCE OF THE CRYSTAL GROWTH RATE IN POLAR GLACIERS

1987 ◽  
Vol 48 (C1) ◽  
pp. C1-661-C1-662 ◽  
Author(s):  
J. R. PETIT ◽  
P. DUVAL ◽  
C. LORIUS
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Temperature Dependence ◽  
Crystal Growth Rate

Comparison of copper sulphate pentahydrate growth rates determined by different methods

1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Fluidized Bed ◽  
Growth Rates ◽  
Copper Sulphate ◽  
Crystal Growth Rate ◽  
Effect Of Temperature ◽  
Rotating Disc ◽  
Shape Factors ◽  
Data Treatment

Crystal growth rates of copper sulphate pentahydrate (CuSO4.5 H2O) determined by different authors and methods are compared. The methods included in this comparison are: (i) Measurement on a fixed crystal suspended in a streaming solution, (ii) measurement on a rotating disc, (iii) measurement in a fluidized bed, (iv) measurement in an agitated suspension. The comparison involves critical estimation of the supersaturation used in measurements, of shape factors used for data treatment and a correction for the effect of temperature. Conclusions are drawn for the choice of values to be specified when data of crystal growth rate measurements are published.

Optical resolution of N-formylphenylalanine succeeds by crystal growth rate differences of diastereomeric salts

2007 ◽  
Vol 18 (2) ◽  
pp. 260-264 ◽  
Author(s):  
Laura Bereczki ◽  
Emese Pálovics ◽  
Petra Bombicz ◽  
György Pokol ◽  
Elemér Fogassy ◽  
...  
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Optical Resolution ◽  
Crystal Growth Rate ◽  
Diastereomeric Salts

Crystal-growth kinetics of protein single crystals along capillary tubes in the gel-acupuncture technique

1999 ◽  
Vol 55 (2) ◽  
pp. 577-580 ◽  
Author(s):  
Abel Moreno ◽  
Manuel Soriano-García
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Capillary Tube ◽  
Crystal Growth Rate ◽  
Equilibrium Studies ◽  
Acta Cryst ◽  
Average Growth ◽  
X Ray Crystallography ◽  
Growing Cell ◽  
Kinetics Of

In attempts to obtain protein crystals of a sufficient size for structural studies, lack of knowledge of the physicochemical properties of protein solutions and of their crystal-growth behaviour lead to a bottleneck for drug design as well as for X-ray crystallography. Most formal investigations on crystal-growth phenomena have been focused on equilibrium studies, where the protein is soluble, and on the kinetics of crystal growth, which is related to both nucleation and crystal-growth phenomena. The aim of this work is to measure the crystal-growth rate along a capillary tube used as a growing cell. These experiments were carried out using the gel-acupuncture technique [García-Ruiz et al. (1993). Mater. Res. Bull. 28, 541–546; García-Ruiz & Moreno (1994). Acta Cryst. D50, 484–490; García-Ruiz & Moreno (1997). J. Cryst. Growth, 178, 393–401]. Crystal-growth investigations took place using lysozyme and thaumatin I as standard proteins. The maximum average growth rate obtained in the lower part of the capillary tube was about 35 Å s−1 and the minimum average growing rate in the upper part of the capillary tube was about 8 Å s−1. The crystal-growth rate as a function of the supersaturation was experimentally estimated at a constant height along the capillary tube.

Phase separation in undercooled molten Pd80Si20: Part I

1999 ◽  
Vol 14 (9) ◽  
pp. 3653-3662 ◽  
Author(s):  
K. L. Lee ◽  
H. W. Kui
Keyword(s):  
Growth Rate ◽  
Phase Separation ◽  
Crystal Growth ◽  
Grain Refinement ◽  
Crystallization Temperature ◽  
Sharp Decrease ◽  
Nucleation And Growth ◽  
Crystal Growth Rate ◽  
Large Undercooling ◽  
Kinetic Crystallization

Three different kinds of morphology are found in undercooled Pd80Si20, and they dominate at different undercooling regimens ΔT, defined as ΔT = T1 – Tk, where T1 is the liquidus of Pd80Si20 and Tk is the kinetic crystallization temperature. In the small undercooling regimen, i.e., for ΔT ≤ 190 K, the microstructures are typically dendritic precipitation with a eutecticlike background. In the intermediate undercooling regimen, i.e., for 190 ≤ ΔT ≤ 220 K, spherical morphologies, which arise from nucleation and growth, are identified. In addition, Pd particles are found throughout an entire undercooled specimen. In the large undercooling regimen, i.e., for ΔT ≥ 220 K, a connected structure composed of two subnetworks is found. A sharp decrease in the dimension of the microstructures occurs from the intermediate to the large undercooling regimen. Although the crystalline phases in the intermediate and the large undercooling regimens are the same, the crystal growth rate is too slow to bring about the occurrence of grain refinement. Combining the morphologies observed in the three undercooling regimens and their crystallization behaviors, we conclude that phase separation takes place in undercooled molten Pd80Si20.

Evaluation of FCAW Consumables for Offshore and Arctic Structure Fabrication

1993 ◽  
Vol 115 (1) ◽  
pp. 76-82 ◽  
Author(s):  
S. R. Bala ◽  
L. Malik ◽  
J. E. M. Braid
Keyword(s):  
Weld Metal ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Inclusion Content ◽  
Ambient Temperatures ◽  
Weld Metals ◽  
Arctic Regions ◽  
Flux Cored Arc Welding ◽  
Crack Tip Opening ◽  
Cored Wires

A primary consideration in the welding of structures for service in Canadian offshore and arctic regions is the toughness of weld metals required at very low ambient temperatures (−30°C to −60°C). To assess the suitability of cored wires for applications in these environments, some currently available commercial consumables for the flux-cored arc welding (FCAW) process were evaluated. Cored wires belonging to four different categories: basic, rutile, metal-cored and innershield, were used to prepare welds with similar welding procedures. Weld metal Charpy V-notch (CVN) and crack tip opening displacement (CTOD) tests were carried out and the effect of weld metal composition, microstructure and inclusion content in the weld metal toughness was examined. The Charpy transition temperatures and the CTOD toughness results indicated that, of the 16 wires tested, there were only seven that would be suitable for critical applications.

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