scholarly journals Analysis of the coefficient of linear relationship, generated by the exponential heating during the welding process for an A36 steel plate

2021 ◽  
pp. 16-21
Author(s):  
Mario Barrera-Moreno ◽  
Rumualdo Servin-Castañeda ◽  
Ismael Calderon-Ramos ◽  
Alejandro Perez-Alvarado
Keyword(s):  
Heat Transfer ◽  
Steel Plate ◽  
Welding Process ◽  
High Hardness ◽  
Metal Plate ◽  
Filler Material ◽  
A36 Steel ◽  
Welding Sequences ◽  
Relationship Of ◽  
The Relationship

The present study presents the relationship of temperature and deformation as well as the analysis of heat transfer and deformation produced during welding of a steel plate. The method consists of strategically welding a base metal plate (A-36) with a high-hardness filler material to obtain an overall increment in wear resistance. However, the thermal cycles generated during welding produced deformation, thus changing the flatness of the plate. Different sequences of welding were applied to obtain a relationship between the heat transfer and deformation. A filler material was applied to 100 holes (1/2” diameter and 8 mm depth) in a ½” steel plate. The temperature and deformation were measured for 3 different welding sequences. Plate 1 reached a final mean temperature of 467 °C and deformation of 0.016”, plate 2 reached 472.9 °C and -0.008”, and plate 3 reached 354.2 °C and 0.020”. The results indicate that the deformation is not function of the final temperature, instead the deformation is function of the slope of the curve temperature vs deformation. The behavior of the curve temperature vs deformation is linear for all cases studied, confirming the findings of the lowest deformation for plate 2 which exhibited the lowest slope.

The Numerical Simulation of Air-Cooled Plate-Fin Heat Exchanger

2011 ◽  
Vol 314-316 ◽  
pp. 1472-1477 ◽  
Author(s):  
Xue Jiang ◽  
Ji Hua Bao ◽  
Yan Yu ◽  
Ming Xia Gu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
3D Model ◽  
Fluid Velocity ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Simulation Results ◽  
Relationship Of ◽  
The Relationship

According to the periodic structure of the plate-fin heat exchanger, 3D model of the heat exchanger is established which simplifies the computation amount of the numerical simulation on flow field and temperature field. The relationship of fluid velocity, temperature, pressure drop and heat transfer coefficient is analyzed. The flow and heat transfer characteristics can be well predicted. Based on the simulation results, the conclusion makes reference to the design of plate-fin heat exchanger.

Effect of Porosity on Residual Stress of 2024-Aluminum GTAW Specimen

2016 ◽  
Vol 872 ◽  
pp. 28-32 ◽  
Author(s):  
Pattarawadee Poolperm ◽  
Wasawat Nakkiew
Keyword(s):  
Residual Stress ◽  
Aluminum Alloys ◽  
Welding Speed ◽  
Fatigue Crack Initiation ◽  
Welding Process ◽  
The Body ◽  
Tensile Residual Stress ◽  
Welding Parameters ◽  
Relationship Of ◽  
The Relationship

Aluminum alloys are used widely in many applications due to its low in density which can lead to a lightweight product. A high percentage of Cu in the chemical composition of the 2024 aluminum alloys helps withstand the occurrence of corrosion as well. Thus, aluminum alloy grade 2024 is used as a material for several parts in aircraft and spacecraft components, (e.g. the body of commercial airplanes), as well as parts in many other applications. Gas Tungsten Arc Welding (GTAW) is used widely in joining material parts together. Inappropriate welding parameters usually cause problems such as porosity in the welding. The occurrence of porosity is undesirable in welding because it can affect the strength of the welding area as well as other properties. Tensile residual stress near the surface of the material expedites the fatigue crack initiation. The relationship of porosity and residual stress for GTAW parts was very limited in literatures. Therefore, the objective of this research was to investigate the relationship of porosity to the occurrence of residual stress after the welding process. Full factorial design of experimental technique was used for setting up welding conditions of the GTAW. The specimen with highest porosity was selected for further analysis of its effect on residual stress. Porosity was analyzed by the radiographic testing (RT) and the residual stress was measure by X-ray diffraction (XRD) using sin2 method. The results showed that the highest porosity in the welded bead was found at the current of 130 A, the welding speed of 210 mm./min., and the wire feed rate of 700 mm./min. The results also suggested that lower current and welding speed caused an increase in porosity. The residual stress results on both longitude and transverse directions showed tensile residual stress at locations around the welded bead area.

The Relationship of the External Surface Area of Birds to Skin Surface Area and Body Mass

1978 ◽  
Vol 76 (1) ◽  
pp. 185-189 ◽  
Author(s):  
GLENN E. WALSBERG
Keyword(s):  
Heat Transfer ◽  
Surface Area ◽  
Body Mass ◽  
External Surface ◽  
Bird Species ◽  
Skin Surface ◽  
External Surface Area ◽  
Relationship Of ◽  
The Relationship

Data from 12 bird species reveal that skin surface area averages 23 % larger than the external surface area of the plumage. Use of skin surface area instead of the area of the external plumage surface may produce large errors in heat-transfer analyses.

Some comments on heat-transfer laws for fine wires

1972 ◽  
Vol 51 (3) ◽  
pp. 487-495 ◽  
Author(s):  
L. J. S. Bradbury ◽  
I. P. Castro
Keyword(s):  
Heat Transfer ◽  
Time Constants ◽  
Transfer Rates ◽  
Flow Past ◽  
Semi Empirical ◽  
Relationship Of ◽  
The Relationship

The semi-empirical heat-transfer laws of Collis & Williams (1959) and Davies & Fisher (1964) give values of the heat-transfer rates for the flow past fine wires which are generally very different from one another. This paper describes some measurements of heat-transfer and convective time constants which show that the relationship of Collis & Williams is the more representative expression.

scholarly journals The Effects of Transient Temperature around Welds on Mechanical Properties of A36 Steel Plate

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Mohammad Jufri
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Steel Plate ◽  
Welding Process ◽  
Hardness Test ◽  
Production Quality ◽  
Transient Temperature ◽  
Body Parts ◽  
A36 Steel ◽  
Thermal Tensioning

There are various ways for welding experts to improve their production quality, and one of which is by designing a particular type of welding tool. Besides aiming to replace the function of operator’s body parts, the tool is also able to control buckling distortions, crack propagations, and stress voltage, as well as to save an additional work, which is the heat treatment after welding process. The best method to control buckling distortions from the thin plate is by applying pre-heating and thermal tensioning. Thermal tensioning is the characterization by heat application during welding process. Transient thermal tensioning is a supporting tool around the weld which is given periodical heat by following the movement of arc welding. The purpose of this research was to minimize distortions and maximize the performance (mechanical properties) of welding joints shaped due to the transient temperature application during the welding process. The method employed in this research was experiment by using A36 steel plate with transient temperature variation of 100, 200, and 300oC, with velocity of 8 mm/s and heater (toutch) distance of 4, 6, and 8 cm. In this research, the researcher conducted tensile-strength test according to the JIS G 3101 standard and hardness test around weld, HAZ (Heat Affected Zone), and parent metal.The findings showed that the change of transient temperature and heater distance affected the mechanical properties (hardness and tensile strength) of A36 steel. The highest level of hardness was obtained in the temperature of 200°C and heater distance of 6 cm, which was as much as 404 VHN. The highest level of tensile strength was obtained in the temperature of 200°C and heater distance variation of 8 cm with yield stress of 302 Mpa and maximum tensile strength of as much as 491 Mpa.

M806 The Relationship of Heat Transfer Characteristics and Structures in Wood

2015 ◽  
Vol 2015.90 (0) ◽  
pp. 370
Author(s):  
Takayuki MASUDA ◽  
Yoshiki NOGUCHI ◽  
Yoichi SHIOMI ◽  
Daisuke TAWARA
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Relationship Of ◽  
The Relationship

Formation and Distribution Mechanism of Intermetallic Compounds of Al/Mg Joint with Zn Transition Metal

2014 ◽  
Vol 597 ◽  
pp. 276-279
Author(s):  
Qiong Gao ◽  
Ke Hong Wang ◽  
Heng Ma ◽  
Wei Guo Feng
Keyword(s):  
Mechanical Property ◽  
Solid Solution ◽  
Transition Metal ◽  
Weld Seam ◽  
Welding Process ◽  
Al Alloy ◽  
6061 Al Alloy ◽  
Relationship Of ◽  
The Relationship ◽  
Microstructure And Mechanical Property

6061 Al alloy and AZ31B Mg alloy were joined by lapping TIG welding process with Zn transition metal. The formation and distribution mechanism of IMCs of Al/Mg joint, and the relationship of microstructure and mechanical property were discussed. The introduction of Zn transition metal reduces the Mg/Al IMCs effectively. The microstructure in the fusion zone near the Mg substrate composes of three regions. B zone contains of only MgZn2 IMCs. That is the place of highest micro-hardness in the weld seam. A and C zones characterize with solid solution precipitated on the MgZn2 basement which can enhance the ductility of Mg/Al joint. This result indicates that increasing the solid solution precipitated on IMCs can improve the mechanical property of Mg/Al joint.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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