Development of operating and metallurgical practices for Lukens’ 150-ton vacuum degassing unit

JOM ◽  
1966 ◽  
Vol 18 (5) ◽  
pp. 623-627
Author(s):  
E. L. Fogleman ◽  
H. W. Wilt ◽  
R. M. Smailer
Keyword(s):  
Author(s):  
C.K. Hou ◽  
C.T. Hu ◽  
Sanboh Lee

The fully processed low-carbon electrical steels are generally fabricated through vacuum degassing to reduce the carbon level and to avoid the need for any further decarburization annealing treatment. This investigation was conducted on eighteen heats of such steels with aluminum content ranging from 0.001% to 0.011% which was believed to come from the addition of ferroalloys.The sizes of all the observed grains are less than 24 μm, and gradually decrease as the content of aluminum is increased from 0.001% to 0.007%. For steels with residual aluminum greater than 0. 007%, the average grain size becomes constant and is about 8.8 μm as shown in Fig. 1. When the aluminum is increased, the observed grains are changed from the uniformly coarse and equiaxial shape to the fine size in the region near surfaces and the elongated shape in the central region. SEM and EDAX analysis of large spherical inclusions in the matrix indicate that silicate is the majority compound when the aluminum propotion is less than 0.003%, then the content of aluminum in compound inclusion increases with that in steel.


Alloy Digest ◽  
1979 ◽  
Vol 28 (4) ◽  

Abstract Cabot ESR HY 140 is a 5Ni-Cr-Mo-V alloy steel produced by electric-furnace melting, vacuum degassing and electroslag remelting (ESR) by use of small-heat-size technology. Electroslag refining improves cleanliness and lowers the sulfur content to provide improved isotropy, ductility and toughness. This steel is capable of developing a minimum yield strength of 140,000 psi with an optimum combination of hardenability, temperability, weldability, formability, toughness and fatigue properties. It meets many special requirements for petrochemical applications. This datasheet provides information on composition, physical properties, and elasticity as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-358. Producer or source: Cabot Corporation, Machinery Division.


Author(s):  
Manas Kumar Mondal ◽  
Govind Sharan Gupta ◽  
Shin-ya Kitamura ◽  
Nobuhiro Maruoka

Recently, the demand of the steel having superior chemical and physical properties has increased for which the content of carbon must be in ultra low range. There are many processes which can produce low carbon steel such as tank degasser and RH (Rheinstahl-Heraeus) processes. It has been claimed that using a new process, called REDA (Revolutionary Degassing Activator), one can achieve the carbon content below 10ppm in less time. REDA process, in terms of installment cost, is in between the tank degasser and RH processes. As such, REDA process has not been studied thoroughly. Fluid flow phenomena affect the decarburization rate the most besides the chemical reaction rate. Therefore, momentum balance equations along with k-? turbulent model have been solved for gas and liquid phases in two-dimension (2D) for REDA process. The fluid flow phenomena have been studied in details for this process by varying gas flow rate, depth of immersed snorkel in the steel, diameter of the snorkel and change in vacuum pressure. It is found that the design of the snorkel affects the melt circulation of the bath significantly.


2015 ◽  
Vol 3 (5) ◽  
pp. 2128-2134 ◽  
Author(s):  
Hongzan Song ◽  
Ningning Zhao ◽  
Weichao Qin ◽  
Bing Duan ◽  
Xiaoya Ding ◽  
...  

High-performance NCPE has been fabricated by using unidirectional freezing method, liquid crystal self-templating approach and vacuum degassing method.


2021 ◽  
Author(s):  
Long-Chao Huang ◽  
Dengke Chen ◽  
De-Gang Xie ◽  
Suzhi Li ◽  
Ting Zhu ◽  
...  

Abstract Hydrogen embrittlement jeopardizes the use of high-strength steels as critical load-bearing components in energy, transportation, and infrastructure applications. However, our understanding of hydrogen embrittlement mechanism is still obstructed by the uncertain knowledge of how hydrogen affects dislocation motion, due to the lack of quantitative experimental evidence. Here, by studying the well-controlled, cyclic, bow-out movements of individual screw dislocations, the key to plastic deformation in α-iron, we find that the critical stress for initiating dislocation motion in a 2 Pa electron-beam-excited H2 atmosphere is 27~43% lower than that under vacuum conditions, proving that hydrogen lubricates screw dislocation motion. Moreover, we find that aside from vacuum degassing, dislocation motion facilitates the de-trapping of hydrogen, allowing the dislocation to regain its hydrogen-free behavior. Atomistic simulations reveal that the observed hydrogen-enhanced dislocation motion arises from the hydrogen-reduced kink nucleation barrier. These findings at individual dislocation level can help hydrogen embrittlement modelling in steels.


2013 ◽  
Vol 40 (4) ◽  
pp. 290-297 ◽  
Author(s):  
K Riyahimalayeri ◽  
P Ölund

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