scholarly journals Analisis Variasi Included Angle terhadap Distorsi pada Sambungan Las SMAW

2018 ◽  
Vol 3 (1) ◽  
pp. 12-18
Author(s):  
Prihatno Kusdiyarto ◽  
Riswan Dwi Djatmiko

The aim of this study is to determine the effects of included angle dimension on the distortion of carbon steel V-groove butt joint using a single pass welding methods. Specimens being studied were AISI 1025 low carbon steel in the form of 1/2 inch-thick plates. The steels were easily weld and were assumed as homogeneous and isotropic; therefore, three specimens for each treatment are adequate. The experiment treated the v-groove shape as independent variable and the distortion as dependent variable. The results show that there is an effect of v-groove dimensions on the distortion of the carbon steels butt joint.. The distortion and their respective angle dimensions are 0.58˚ for the 55˚ angle, 0.78˚ for the 60˚ angle, and 1.02˚ for the 65˚ angle. The magnitude of the distortions are well below 3˚, which is the permissible amount for the butt joint distortion criteria.Tujuan penelitian ini untuk mengetahui ada tidaknya pengaruh dimensi included angle (bentuk kampuh) terhadap distorsi pada sambungan ujung baja karbon dengan metode pengelasan SMAW single pass. Dalam penelitian ini obyek yang diteliti adalah baja karbon rendah type AISI 1025 yang berupa plat strip dengan ketebalan 1/2 inchi. Baja jenis ini merupakan bahan yang mudah dilas dan diasumsikan homogen dan isotropic, sehingga sampel yang diambil cukup tiga buah pada masing-masing perlakuan. Bentuk included angle merupakan variabel bebas dan distorsi adalah variabel terikat. Hasil penelitian menunjukkan adanya pengaruh dimensi included angle terhadap distorsi pada sambungan ujung baja karbon. Besarnya distorsi pada sambungan dengan dimensi sudut 55˚ sebesar 0,58˚, 60˚ sebesar 0,78˚, 65˚ sebesar 1,02˚. Hal ini memberikan informasi bahwa variasi sudut included angle tersebut menghasilkan distorsi di bawah 3˚, sehingga masih termasuk dalam batas yang diijinkan persyaratan kelolosan sambungan las.

2017 ◽  
Vol 740 ◽  
pp. 93-99
Author(s):  
Muhammad Hafizuddin Jumadin ◽  
Bulan Abdullah ◽  
Muhammad Hussain Ismail ◽  
Siti Khadijah Alias ◽  
Samsiah Ahmad

Increase of soaking time contributed to the effectiveness of case depth formation, hardness properties and carbon content of carburized steel. This paper investigates the effect of different soaking time (7-9 hours) using powder and paste compound to the carburized steel. Low carbon steels were carburized using powder and paste compound for 7, 8 and 9 hours at temperature 1000°C. The transformation of microstructure and formation carbon rich layer was observed under microscope. The microhardness profiles were analyzed to investigate the length of case depth produced after the carburizing process. The increment of carbon content was considered to find the correlation between types of carburizing compound with time. Results shows that the longer carburized steel was soaked, the higher potential in formation of carbon rich layer, case depth and carbon content, which led to better hardness properties for carburized low carbon steel. Longer soaking time, 9 hours has a higher dispersion of carbon up to 41%-51% compare to 8 hours and 7 hours. By using paste carburizing, it has more potential of carbon atom to merge the microstructure to transform into cementite (1.53 wt% C) compare to powder (0.97 wt% C), which increases the hardness of carburized steel (13% higher).


1987 ◽  
Vol 109 (3) ◽  
pp. 257-264 ◽  
Author(s):  
E. M. Kopalinsky ◽  
P. L. B. Oxley

Experiments show that the cold working of low carbon steel work materials can improve their machinability by reducing cutting forces and improving surface finish and tool life. The somewhat paradoxical result of reducing cutting forces by cold working a material so that its hardness is increased is explained in this paper by using a machining theory which takes account of the flow stress properties of the work material and can thus allow for the effects of cold working.


2009 ◽  
Vol 79-82 ◽  
pp. 143-146
Author(s):  
Jiang Hua Ma ◽  
Dong Ping Zhan ◽  
Zhou Hua Jiang ◽  
Ji Cheng He

In order to understand the effects of deoxidizer such as aluminium, titanium and magnesium on the impact toughness of heat affected zone (HAZ), three low carbon steels deoxidized by Ti-Al, Mg and Ti-Mg were obtained. After smelting, forging, rolling and welding simulation, the effects of Al, Ti and Mg addition on the impact toughness of HAZ in low carbon steel were studied. The inclusion characteristics (size, morphology and chemistry) of samples before welding and the fracture pattern of the specimens after the Charpy-type test were respectively analyzed using optical microscope and scanning electron microscopy (SEM). The following results were found. The density of inclusion in Ti-Mg deoxidized steel is bigger than Ti-Al deoxidized steel. The average diameter is decreased for the former than the latter. The addition of Ti-Mg can enhance the impact toughness of the HAZ after welding simulation. The maximal value of the impact toughness is 66.5J/cm2. The complex particles of MgO-TiOx-SiO2-MnS are most benefit to enhance impact toughness. The improvement of HAZ is attributable to the role of particle pinning and the formation of intergranular ferrite.


2016 ◽  
Vol 369 ◽  
pp. 59-64
Author(s):  
Muhammad Ali Abro ◽  
Dong Bok Lee

A low carbon steel was hot-dip aluminized, and corroded in the N2/0.4%H2S-mixed gas at 650-850°C for 20-50 h in order to find the effect of aluminizing on the high-temperature corrosion of the low carbon steel in the H2S environment. A thin Al topcoat and a thick Al-Fe alloy layer that consisted primarily of Al5Fe2 and some FeAl and Al3Fe formed on the surface after aluminizing. The corrosion rate increased with an increase in temperature. Hot-dip aluminizing increased the corrosion resistance of the carbon steel through forming a thin protective α-Al2O3 scale on the surface. The α-Al2O3 scale was susceptible to spallation. During corrosion, internal voids formed in the Al-Fe alloy layer, where the Al5Fe2, AlFe, and Al3Fe compounds gradually transformed through interdiffusion.


2017 ◽  
Vol 36 (4) ◽  
pp. 347-357 ◽  
Author(s):  
Yang Li ◽  
Jing Wang ◽  
Jiaquan Zhang ◽  
Changgui Cheng ◽  
Zhi Zeng

AbstractThe surface quality of slabs is closely related with the initial solidification at very first seconds of molten steel near meniscus in mold during continuous casting. The solidification, structure, and free deformation for given steels have been investigated in droplet experiments by aid of Laser Scanning Confocal Microscope. It is observed that the appearances of solidified shells for high carbon steels and some hyper-peritectic steels with high carbon content show lamellar, while that for other steels show spherical. Convex is formed along the chilling direction for most steels, besides some occasions that concave is formed for high carbon steel at times. The deformation degree decreases gradually in order of hypo-peritectic steel, ultra-low carbon steel, hyper-peritectic steel, low carbon steel, and high carbon steel, which is consistent with the solidification shrinkage in macroscope during continuous casting. Additionally, the microstructure of solidified shell of hypo-peritectic steel is bainite, while that of hyper-peritectic steel is martensite.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012149
Author(s):  
Roland Tolulope Loto ◽  
Cleophas Akintoye Loto ◽  
Richard Leramo ◽  
Babatunde Oyebade

Abstract Corrosion inhibition of carbon steels with organic compounds exhibiting effective corrosion inhibition is an on-going research. The corrosion inhibition of low carbon steel in 1M HCl solution by the combined admixture of vanillin and benzonitrile (VBN), and salvia officinalis with lavendulan officinalis (SLV) was studied by weight loss method. Results obtained show that VBN and SLV performed effectively with maximum inhibition efficiency 91.03% at 1.5% VBN concentration and 97.89% at 5% SLV concentration. The inhibition efficiency of VBN increased with concentration but decreased with exposure time compared to the values obtained for SLV which showed non-dependence on concentration and exposure time after 1% SLV concentration. Correlation plots of inhibition efficiency versus inhibitor concentration show VBN to be more concentration dependent in performance. Calculated data for standard deviation shows the degree of variation from mean values for both compounds is significant at low inhibitor concentration due to time dependence action. Statistical analysis through ANOVA shows inhibitor concentration overwhelmingly influences the inhibition performance of the despite even though exposure time is statistically relevant to minimal degree.


2018 ◽  
Vol 385 ◽  
pp. 455-460
Author(s):  
Denis Pustovoytov ◽  
Alexander Pesin ◽  
Alexander P. Zhilyaev ◽  
Georgy I. Raab

Grain refinement by severe plastic deformation can make conventional metallic materials several times stronger, but it leads to dramatic loss of their ductility. Gradient structure through the thickness of processed material represents a new strategy for producing a superior combination of high strength and good ductility. In gradient metallic materials the grain size increases gradually from nanoscale at the surface to coarse-grained in the core. Strain gradient can be considered as a mechanism of creating of such microstructures. Providing of predetermined strain gradient in the metallic materials can be achieved by asymmetric rolling (AR), when circumferential speeds of the top and bottom work rolls are different. Since the AR is a continuous process, it has great potential for industrial production of large-scaled sheets. Searching the optimal process parameters which can provide special strain gradients through sheet thickness is very important. This paper presents the distributions of the effective strain through sheet thickness of low-carbon steel AISI 1015 processed by a single-pass AR. Influence of process parameters was investigated by the finite element method with using software DEFORM 2D. Extremely high strain gradient e ≈ 4...8 through sheet thickness during a single-pass AR was found. FE analysis of the deformation characteristics, presented in this study, can be used for optimization of the AR process as a method of fabrication of metallic materials with gradient microstructures.


2018 ◽  
Vol 941 ◽  
pp. 230-235
Author(s):  
Ling Ling Yang ◽  
Tatsuya Nakagaito ◽  
Yoshimasa Funakawa ◽  
Katsumi Kojima

Yield strength of low carbon mild steel decreases when temper-rolling is applied to release yield point elongation. Generally mobile dislocation used to be considered as the cause of the YS lowering. However from Bailey-Hirsch theory, strength should be higher with temper-rolling because of the increase of dislocation density. To newly explain the lowering yield strength by temper-rolling, standing at the point that a few ppm carbon change Hall-Petch coefficient , decrease in yield strength by temper-rolling is investigated using an ultra-low carbon steel. Yield strength of steel with the small amount of solute carbon increased after 2% temper-rolling and didn’t change after aging. On the other hand, yield strength of steel with the high amount of solute carbon decreased after 2% temper-rolling and increased again after aging. Despite solute carbon content, the Hall-Petch σ0 increased by dislocation strengthening of temper-rolling. Hall-Petch coefficient ky of low solute carbon steel remained at the low level even after temper-rolling or aging , however, that of high solute carbon steels significantly decreased after temper-rolling and increased again after aging. Yield strength reduction of the high solute carbon steel can be attributed to the decrease of ky.


Author(s):  
A.M. Dmitriev ◽  
N.V. Korobova

The quality of parts such as deep cylindrical cups made by cold forging from low-carbon steel and sintered billets from iron powder is compared. Technological processes from production of iron-based powder parts and press equipment used in mechanical engineering and in powder metallurgy are described. Cold forging of powder billets and billets from low-carbon steels is carried out on press specialized for extrusion with the creation of actively directed contact friction stresses between the deformable billet and the die. It is shown that cold extrusion of cup-type parts with actively directed contact friction stresses makes it possible to manufacture parts from iron-based powder with density equal to 98...99 % of the theoretical iron density. However parts from low-carbon steel have strength limit greater than that of powder parts. Powder cups do not have the anisotropy of properties typical for cups from low-carbon steels.


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