Measurement of Cooling Curves in Centrifugal Casting of a Ferrous Alloy

2008 ◽  
Author(s):  
Romulo Heringer ◽  
Ma´rio Boccalini ◽  
Marcelo A. Martorano ◽  
Cla´udia R. Serantoni

A sensor was developed to measure the cooling curves inside a ferrous alloy during its solidification as centrifugally cast tubes. The temperature evolution at some points within the alloy is necessary to evaluate the heat transfer through the outer surface of the tube during the centrifugal casting process. Serious difficulties exist in this type of measurement, because of the rotation of the mold and the relatively high temperature at which the ferrous alloy is poured. The sensor consists of sheathed thermocouples positioned by a convenient support internally to the rotating mold, within the metal layer. Although the sensor is subjected to thermal and mechanical stresses during the melt pouring and solidification, it must maintain its mechanical and thermal characteristics to temperatures of the order of the melting point of the ferrous alloy. Therefore, the thermocouple sheaths and support have been made of refractory metals, namely, tantalum and niobium, to resist the high temperature. Moreover, the sensor was designed to have low thermal inertia, allowing its temperature to increase above the liquidus temperature of the alloy before solidification of the surrounding liquid metal. Because the sensor is embedded in the solidified tube after solidification, a special design was necessary to allow stripping the tube out of the mold without disturbing the system.

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Manu Sam ◽  
N. Radhika

A functionally graded Cu–10Sn–5Ni metal matrix composite (MMC) reinforced with 10 wt % of Al2O3 particles was fabricated using the centrifugal casting process with dimension Φout100 × Φin85 × 100 mm. The mechanical and wear resistance of the composite has been enhanced through heat treatment. Samples from of the inner zone (9–15 mm) were considered for heat treatment, as this zone has higher concentration of less dense hard reinforcement particles. The samples were solutionized (620 °C/60 min) and water quenched followed by aging at different temperatures (400, 450, and 550 °C) and time (1–3 h). Optimum parametric combination (450 °C, 3 h) with maximum hardness (269 HV) was considered for further analysis. Dry sliding wear experiments were conducted based on Taguchi's L27 array using parameters such as applied loads (10, 20, and 30 N), sliding distances (500, 1000, and 1500 m), and sliding velocities (1, 2, and 3 m/s). Results revealed that the wear rate increased with load and distance whereas it decreased initially and then increased with velocity. Optimum condition for maximum wear resistance was determined using signal-to-noise (S/N) ratio. Analysis of variance (ANOVA) predicted the major influential parameter as load, followed by velocity and distance. Scanning electron microscope (SEM) analysis of worn surfaces predicted the wear mechanism, observing more delamination due to increase in contact patch when applied load increased. Results infer 8% increase in hardness after heat treatment, making it suitable for load bearing applications.


1978 ◽  
Vol 100 (3) ◽  
pp. 423-427 ◽  
Author(s):  
G. A. Saltzman

In extrusion and injection molding, centrifugally cast metallurgical coatings are often utilized to provide wear resistance in the barrel of the molding machine. The need for wear resistance is a result of two potential sources of wear, a screw or plunger that operates within the barrel, and the plastic being processed. Adhesive wear occurs under abnormal operating conditions when the screw bears against the barrel bore. Abrasive wear may result from certain additives used to modify the properties of the plastics. An in situ centrifugal casting process used for production of wear resistant coatings metallurgically bonded to the bores of heavy wall metal tubes is described. Characteristics of industry standard metallurgical coating alloys, a martensitic white iron, a Co-Ni-Cr-B alloy and a composite with tungsten carbide dispersed in a Ni-base alloy matrix are given. Metal-to-metal wear-compatibility tests are discussed.


Alloy Digest ◽  
1996 ◽  
Vol 45 (9) ◽  

Abstract Wiscalloy 25-35Nb is a high-temperature cast heat-resistant stainless steel with good creep-rupture properties. The alloy is centrifugally cast and is often used as petrochemical furnace tubing. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on casting and joining. Filing Code: SS-654. Producer or source: Wisconsin Centrifugal.


Alloy Digest ◽  
1978 ◽  
Vol 27 (6) ◽  

Abstract THERMALLOY 63W is a cast nickel-chromium-tungsten-iron alloy produced for service at temperature up to 1900 F. Centrifugally cast reformer tubes comprise one of its high-temperature applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-352. Producer or source: Abex Corporation, Engineered Products Division.


Author(s):  
Williams S. Ebhota ◽  
Akhil S. Karun ◽  
Freddie L. Inambao

The study investigates the application of centrifugal casting process in the production of a complex shape component, Pelton turbine bucket. The bucket materials examined were functionally graded aluminium A356 alloy and A356-10%SiCp composite. A permanent mould for the casting of the bucket was designed with a Solidworks software and fabricated by the combination of CNC machining and welding. Oil hardening non-shrinking die steel (OHNS) was chosen for the mould material. The OHNS was heat treated and a hardness of 432 BHN was obtained. The mould was put into use, the buckets of A356 Alloy and A356-10%SiCp composite were cast, cut and machined into specimens. Some of the specimens were given T6 heat treatment and the specimens were prepared according to the designed investigations. The micrographs of A356-10%SiCp composite shows more concentration of SiCp particles at the inner periphery of the bucket. The maximum hardness of As-Cast A356 and A356-10%SiCp composite were 60 BRN and 95BRN respectively, recorded at the inner periphery of the bucket. And these values appreciated to 98BRN and 122BRN for A356 alloy and A356-10%SiCp composite respectively after heat treatment. The prediction curves of the ultimate tensile stress and yield tensile stress show the same trend as the hardness curves.


2015 ◽  
Vol 101 (9) ◽  
pp. 488-493 ◽  
Author(s):  
Hisao Esaka ◽  
Yoshimasa Kataoka ◽  
Kei Shinozuka

2019 ◽  
Vol 27 (2) ◽  
pp. 51-54 ◽  
Author(s):  
E. S. Skorbyaschensky ◽  
V. F. Bashev ◽  
A. N. Polishko ◽  
S. N. Antropov

The method of quenching in tin melt was tested for low-weight parts with a large specific surface, made of a number of steels with a high temperature of the onset of martensitic transformation. The advantages of this method in comparison with traditional hardening technologies are established, as well as regularities in the change of cooling curves for various mass ratios of the part and the quencher are revealed. The practical possibility of adjusting the cooling rates in the process of hardening in various temperature ranges in order to optimize the phase ratio in steel while maintaining the possibility of preventing the occurrence of microcracks is shown.


2010 ◽  
Vol 139-141 ◽  
pp. 557-560
Author(s):  
Wen Bin Sheng ◽  
Chun Xue Ma ◽  
Wan Li Gu

TiAl-based alloy valves were manufactured by combining charges compressed /vacuum arc melting (VA)/ induction skull melting (ISM) procedure with permanent mold centrifugal casting method. Microstructures, compositions and mechanical properties of as-cast and hot isostatical pressed (HIPed) valves are detected. Results show that the permanent mold centrifugal casting process obviously refines the size of grain in TiAl alloy and the tensile strength of as-cast and HIPed valves are 550MPa and 580MPa at 20°C, 370MPa and 470MPa at 815°C, respectively. As-cast specimens show ~0% elongation at 20°C and 1~2% at 815°C, while HIPed ones show an elongation of 1~2% at room temperature and about 10% at 815°C. Furthermore, a 200-hour test was carried out with CA4GE-engine, which demonstrated the possibility of as-cast TiAl alloy valves for the substitution of present steel ones.


Author(s):  
Wei Minghui ◽  
Cai Wei ◽  
Xu Mingze ◽  
Deng Shuang

Abstract Downhole high temperature environment is an important factor affecting the performance of downhole instrument electronic system.At present, various active cooling technologies and passive cooling technologies have been proposed to reduce the temperature of downhole electric circuit system.However, passive cooling technologies can only provide limited cooling capacity for drilling tools under high temperature environment, and the duration of cooling is short, which can not meet the long-time drilling task.This paper presents an Active cooling system(ACS)for downhole electronics and the effects of different temperatures on the performance of electronic components are analyzed.The ACS mainly includes a micro supercharger, condenser tube, evaporation pipe, capillary tube and refrigerant.The theoretical analysis of heat transfer and refrigerant capacity in high temperature environment is carried out.The thermal characteristics of the ACS is evaluated experimentally.The results show that the temperature of electronic components can be reduced to below 163°C in the 200°C downhole environment and components.The geomagnetic field data measured by electronic components at room temperature, 200 °C and with ACS are compared.The results show that ACS can keep electronic components working normally.


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