• Title/Summary/Keyword: Mild steel

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A Study on Forming for Brake Pipe of Automobiles using Finite Element Method (유한요소법을 이용한 자동차용 브레이크 파이프의 성형에 관한 연구)

  • Min, Byeong-Hyeon;Jea, Wone-Soo;Ye, Sang-Don
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.7 no.3
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    • pp.47-49
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    • 2008
  • The brake pipe is important part in automobile. The brake pipe have to prevent crack, fracture and defects for braking in safety. Especially, shape of ends of pipe has influence on ability of brake. Based on the procedure of process design, in this paper, the forming operation is designed by finite element method. Design variable and response value was selected shape of die and damage factor. To improve die that performed FEM and compared results of two types of die.

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Studies on the Corrosion Inhibitor (Ⅱ) (Inhibitor에 관한 硏究 (Ⅱ))

  • Lee Kae Soo
    • Journal of the Korean Chemical Society
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    • v.13 no.2
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    • pp.137-140
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    • 1969
  • This investigation was made to evaluate the corrosion inhibiting effects of urotropine for mild steel in HCl. 1) Formaldehyde produced by the decomposition of urotropine also showed positive inhibiting effects. 2) In the presence of the ions, such as $Cu^+$, $Cu^{++}$, $Fe^{+++}$, $SO_3^=$, $SO_4^=$, $NO_2^-$, $NO_3^-$, $Cr_2O_7^=$, the inhibiting capacity of the urotropine was decreased. Alkali and alkaline-earth metal ions had no effects but the halogen ions improved it. 3) From measurements of polarization curves, it was assumed that the anode reaction was more retarded by the urotropine and the halogen.

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The effect of Previous Cutting Process on Surface Roughness in Surface Rolling (표면로울링에서 전가공이 표면조도에 미치는 영향)

  • Yuck, Kweng-Soo;Park, Byung-Sung;Choi, Byung-Kwon
    • Journal of the Korean Society for Precision Engineering
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    • v.5 no.3
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    • pp.91-100
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    • 1988
  • Surface rolling which is one of the plastic deformation have advantages to imporve surface roughness, hardness and fatigue strength with relatively simple processes. In this study, the effect of previous cutting process before rolling on the surface roughness in surface rolling for mild steel was investigated. The results obtained are as follows. (1) Waveness of the previous process has the effect on the precision of the works and coarse waveness resulted in less improvement of the surface roughness. (2) The reduction of diameter and increase of hardness can be obtained at the first rolling process.

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Stress Corrosion Cracking Behavior under Cavitation Erosion-Corrosion in Sea Water-Part (I) (해수환경중 캐비테이션 침식 -부식 하에서의 응력부식균열거동(I))

  • 안석환;임우조
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.2
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    • pp.132-138
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    • 2000
  • The effect of fluid flow on corrosion and erosion-corrosion of metal is a well-recognized phenomenon in pipelines and machinery equipment, and so on. Not only are fluid hydrodynamics important, but also the corrosiveness of the process or production stream affects the corrosion system. Recent research demonstrates that it is possible to erosion-corrosion(E/C) phenomena in terms of hydrodynamics, electrochemical corrosion kinetics and film growth/removal phenomena. Stress corrosion cracking behavior under cavitation erosion-corrosion of mild steel(SS41) was investigated of base metal and weldment under loaded stress. Main result obtained are as follows : 1) The cavitation erosion sensitivity of base metal affected weight loss is more susceptive than heat affected zone, 2) The corrosion sensitivity affected weight loss of welding heat cycle is less susceptive on stress corrosion under cavitation erosion-corrosion than stress corrosion.

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Basic Characteristics of Micro-Fatigue-Cracks on the Unnotched Smooth Specimens (平활材表面 의 微小피勞균열에 관한 基礎的 特性)

  • 서창민;북천영부;결성양치
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.7 no.1
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    • pp.28-35
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    • 1983
  • Quantitative analysis have been carried out on the micro-cracks on the surface and into the depth of unnotched smooth mild steel specimen under cyclic stains by rotating bending fatigue tests. Some of the results are; (1) Cracks initiate at the early stage of fatigue life N$_{I}$/ N$_{f}$=10 to 20%, and propagate during the rest of fatigue life. (2) Coalescence of highly crowded small fatigue cracks of random distribution seems to induce the final fracture at higher stress level. (3) The curves of crack initiation and the equal crack length on the graph of stress versus number of cycles are parallel to the S-N curve. (3) The curves of crack initiation and the equal crack length on the graph of stress versus number of cycles are parallel to the S-N curve. (4) The distributions of micro-surface crack length and depth show the composite Weibull distributions which are approximated to two straight lines separated by the value of transient region between stage I and stage II crack.k.k.

A Study on Prediction of Optimized Penetration Using the Neural Network and Empirical models (신경회로망과 수학적 방정식을 이용한 최적의 용입깊이 예측에 관한 연구)

  • 전광석
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.5
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    • pp.70-75
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    • 1999
  • Adaptive control in the robotic GMA(Gas Metal Arc) welding is employed to monitor the information about weld characteristics and process paramters as well as modification of those parameters to hold weld quality within the acceptable limits. Typical characteristics are the bead geometry composition micrrostructure appearance and process parameters which govern the quality of the final weld. The main objectives of this paper are to realize the mapping characteristicso f penetration through the learning. After learning the neural network can predict the pene-traition desired from the learning mapping characteristic. The design parameters of the neural network estimator(the number of hidden layers and the number of nodes in a layer) were chosen from an error analysis. partial-penetration single-pass bead-on-plate welds were fabricated in 12mm mild steel plates in order to verify the performance of the neural network estimator. The experimental results show that the proposed neural network estimator can predict the penetration with reasonable accuracy and gurarantee the uniform weld quality.

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On the Deformation Analysis of the Brake Tube-End for Automobiles (자동차용 브레이크 튜브 관단부의 성형해석)

  • Han, K.T.;Park, J.S.
    • Journal of Power System Engineering
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    • v.6 no.3
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    • pp.31-35
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    • 2002
  • Brake tube is considered one of the most important parts in automobile. The shape of brake tube end has a great influence on the function of brake, and the quality and productivity of brake tube have relation to die design. The forming process of brake tube end is performed by hydraulic press forming machine. In this paper, the forming processes of tube end for automobile is analyzed and designed to make the optimal form of brake tube end. Also, finite element analysis has been carried out using $DEFORM^{TM}% 3D to predict the optimal shape of brake tube end and the results obtained showed the optimal length between punch and chuck is $1.0{\sim}1.2mm$. The shape of tube end is in good agreement with the finite element simulations and the experimental results.

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Development of Automatic Welding Machine for Fish Trap Frame and Comparison of Shear Strength between Manual and Automatic Work at Welding Point (통발프레임 자동용접장비개발과 용접점에서 수작업과 자동작업의 전단강도 비교에 관한 연구)

  • Han, Chang-Min;Lee, Sang-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.2
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    • pp.129-134
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    • 2017
  • The process of producing a fish trap frame is very complicated and manual, so it is expensive, the quality of the product is unstable, the quality is not guaranteed, the durability is weak, and it cannot be used for a long time. Therefore, we made a fish trap frame-making machine to reduce the manpower and costs and to make robust products. This machine cuts the wire of mild steel to a certain size and then makes the connecting parts into a trapezoid shape by spot welding. In this study, the weld point shear strength between manual and automatic operation was compared and analyzed.

The Relation between Applied Stress and Rebound Hardness Values (부가응력과 반발경도와의 관계)

  • Nahm, S.H.;Kim, S.C.;Jeon, S.B.
    • Journal of the Korean Society for Heat Treatment
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    • v.8 no.4
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    • pp.318-325
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    • 1995
  • Information of change of hardness values during applying load is needed often to control the quality of metal products efficiently, but the relation between applied stress and hardness has not been established. In this paper the theoretical relation between the rebound hardness and stress was examined briefly and the experiment was performed with some materials. Materials used in test were mild steel(SB41), 7-3 brass and copper, which were widely used in the commercial plants. Hardness was measured during stress applied using the Equo-Tip hardness tester as a kind of rebound hardness tester. Hardness values decreased as tensile stress increased, the decreasing rate was effected by the Young's modulus of each material, and the rebound hardness values showed linear relationship with the applied stress in elastic region.

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Effect of gas detonation on response of circular plate-experimental and theoretical

  • Babaei, Hashem;Mostofi, Tohid Mirzababaie;Sadraei, Seyed Hamidreza
    • Structural Engineering and Mechanics
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    • v.56 no.4
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    • pp.535-548
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    • 2015
  • A series of experimental results on thin mild steel plates clamped at the boundary subjected to gas detonation shock loading are presented. Detonation occurred by mixing Acetylene (C2H2)-Oxygen (O2) in various volume ratio and different initial pressure. The applied impulse is varied to give deformation in the range from 6 mm to 35 mm. Analytical modeling using energy method was also performed. Dependent material properties, as well as strain rate sensitivity, are included in the theoretical modeling. Prediction values for midpoint deflections are compared with experimental data. The analytical predictions have good agreement with experimental values. Moreover, it has been shown that the obtained model has much less error compared with those previously proposed in the literature.