scholarly journals THE MAIN GAS PIPELINES MECHANICAL DAMAGE INFLUENCE ON SAFE OPERATION / MAGISTRALINIO DUJOTIEKIO MECHANINIŲ PAŽEIDIMŲ ĮTAKA SAUGIAM EKSPLOATAVIMUI

2016 ◽  
Vol 7 (6) ◽  
pp. 658-663
Author(s):  
Tadas Vilkys ◽  
Vitalijus Rudzinskas
Keyword(s):  
Computer Software ◽  
Mechanical Damage ◽  
Hardness Measurement ◽  
Optical Microscope ◽  
Main Pipeline ◽  
Micro Hardness ◽  
Operational Parameters ◽  
Safe Operation ◽  
Main Pipelines ◽  
Damage Types

The influence of mechanical damage of the gas transmission pipelines on safe pipelines operation was researched in the article. The paper presents the main pipelines damage types with actual parameters and influence on operational parameters. The main pipeline Kaunas – Kaliningrad part, which was removed as no longer usable, was analysed. This damaged part was removed and changed to a new part by a responsible company. The hardness measurement and micro hardness measurement, chemical analysis, impact strength test, metallography analysis with an optical microscope were used in experiments. The analysed pipeline part was also regenerated by the computer software ANSYS, which works by the finite elements method. Straipsnyje nagrinėjama magistralinių dujotiekių mechaninių pažeidimų įtaka saugiam jų eksploatavimui. Darbe pateikti pagrindiniai vamzdynų pažeidimo tipai su jiems būdingais bruožais ir įtaka eksploataciniams parametrams. Ištirta magistralinio dujotiekio Kaunas – Kaliningradas dalis, kuri buvo pašalinta, kaip nebetinkama naudojimui. Tyrimams pasitelktas kietumo ir mikrokietumo matavimas, cheminės analizės tyrimas, smūginio tąsumo bandymas. Mikrostruktūros tyrimams naudotas optinis mikroskopas. Tiriamasis objektas buvo atkurtas kompiuterinės programos, veikiančios baigtinių elementų metodu, ANSYS erdvėje.

scholarly journals Assessment of Seismic Vulnerability of the Main Pipelines in Information Deficiency Conditions

10.12737/208 ◽  
2013 ◽  
Vol 2 (1) ◽  
pp. 20-30
Author(s):  
Котляревский ◽  
Vladimir Kotlyarevskiy ◽  
Ларионов ◽  
Valeriy Larionov ◽  
Александров ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
Seismic Vulnerability ◽  
Experimental Information ◽  
Climatic Conditions ◽  
Main Pipeline ◽  
Pipeline Transport ◽  
Safe Operation ◽  
Main Pipelines ◽  
Oil Pipelines

Operation in difficult climatic conditions and the large extent of the main gas and oil pipelines causes the need of search of new decisions for ensuring the reliable and safe operation of pipeline transport objects. The technique offered in this article is based on the plotting of seismic vulnerability function of the main pipeline embedded in soil by calculated dynamic analysis of stresseddeformed state in conditions of experimental information lack.

scholarly journals PELAPISAN PERMUKAAN DALAM NOSEL ROKET RKX100 DENGAN Cr2C3-NiCr HVOF: OPTIMASI KEKUATAN LEKAT MELALUI VARIASI KEKASARAN PERMUKAAN

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Bondan T.Sofyan ◽  
Yus Prasetyo ◽  
Sayid Ardiansyah ◽  
Yus Prasetyo ◽  
Edy Sofyan
Keyword(s):  
Surface Roughness ◽  
Thermal Spray ◽  
Bonding Strength ◽  
Spray Coating ◽  
Hardness Measurement ◽  
Thermal Spray Coating ◽  
Optical Microscope ◽  
Mechanical Interlocking ◽  
Micro Hardness ◽  
Scanning Electron

Nozzle of RKX100 rocket contributes 30 percent to the total weight of the structure, so that allowing further research on weight reduction. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel) thermal spray layer. A series of study on the characteristics of various type of HVOF coating material have been being conducted. This paper presented the investigation on the HVOF Cr2C3-NiCr thermal spray coating, in particular, the optimization of bonding strength by varying surface roughness of substrates. Characterization included bonding strength test, micro hardness measurement and micro structural observation with optical microscope and scanning electron micriscope (SEM). The results showed that grit blasting pressure increass the surface roughness from 4,54 um to 5.72 um at the pressure of 6 bar. Average micro hardness of the coating was 631 VHN 300. Coating applied to the surface with rougness of 5.42 um possessed the highest bonding strength, 44 MPa. Microstructural observation by using optical microscope and scanning electron microscope (SEM) confirmed dense lamellae structure with variable composition. High coating adherence was found to be due to mechanical interlocking.

scholarly journals Pengaruh Substrat Terhadap Kekerasan Lapisan NiCoCrAlY Yang Terdeposisi Dengan Teknik HVOF[Effect of Different Substrate on Hardness Properties of NiCoCrAlY Coatings Deposited by HVOF Technique]

Metalurgi ◽  
2017 ◽  
Vol 32 (2) ◽  
pp. 91
Author(s):  
Resetiana Dwi Desiati ◽  
Eni Sugiarti ◽  
Endro Junianto ◽  
Erie Martides ◽  
Budi Prawara
Keyword(s):  
Structural Analysis ◽  
Carbon Steel ◽  
High Velocity ◽  
Coating Layer ◽  
Thermal Spraying ◽  
Hardness Measurement ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Coated Layer

Micro structure and micro hardness characterizations have been done on NiCoCrAl coating deposited on different substrate, i..e, carbon steel, nickel chrome and hastealloy. NiCoCrAlY coating was deposited by high velocity oxy fuel (HVOF) thermal spraying technique. Characterization and measurents were applied on all cross section of the coating surfaces. Micro structural analysis was characterized by optical microscope with 40x magnification. Moreover, micro hardness tester was utilized to measure the hardness of the sample with 300 gf for 13 second. The hardness data was measured by calculating the average of 3 position of hardness measurement on substrate before coating, after coating and NiCoCrAl coating layer. According to micro structural analysis, it reveald that the thickness of NiCoCrAlYcoating layer was about  370.76 mm, 92 mm, dan 115.73 on carbon steel, nickel chrome and hastealloy substrate, respectively. Surface morfology showed that the coated layer was not flat and porous structure or void on the coated layer. The porosity of the coated layer might effect the mechanical properties of the sample where high procentase of porosity might reduce the hardness of the sample. The hardness of NiCoCrAlY coating was about 349.95, 315.60 and  311.30 HV for carbon steel, nickel chrome and hastealloy substrate, respectively. The distance from interface between coating layer and substrate might effect hardness measurement. More closer to interface could decrease hardness value and it might caused by interdiffusion of coating elements. Thus would be effect to its mechanical properties.AbstrakTelah dilakukan karakterisasi strukturmikro dan kekerasan mikro pada lapisan NiCoCrAlY yang dideposisikan di atas substrat yang berbeda yaitu baja karbon, nikel krom dan hastealloy. Lapisan NiCoCrAlY dideposisikan menggunakan teknik penyemprotan HVOF (high velocity oxy fuel). Proses karakterisasi dan pengukuran dilakukan pada seluruh lapisan dengan irisan melintang. Karakterisasi strukturmikro diamati dengan menggunakan mikroskop optik dengan perbesaran 40x. Selanjutnya untuk pengukuran kekerasan menggunakan kekerasan mikro dengan beban 300 gf selama 13 detik. Data pengujian kekerasan diperoleh dengan mengukur nilai rata-rata dari 3 posisi uji kekerasan pada masing-masing bagian substrat sebelum dilapisi, setelah dilapisi dan lapisan NiCoCrAlY. Berdasarkan hasil karakterisasi strukturmikro diketahui bahwa lapisan NiCoCrAlY berhasil terdeposisi dengan ketebalan 370,76 mm, 92 mm, dan 115,73 mm masing-masing di atas substrat baja karbon, nikel krom dan hastealloy. Morfologi permukaan lapisan menunjukkan bahwa lapisan yang terdeposisi tidak begitu rata dan masih tampak adanya pori atau lubang di area lapisan NiCoCrAlY yang terbentuk. Porositas dari lapisan sangat berpengaruh pada sifat mekanik, semakin tinggi persentase porositas lapisan maka kekerasan akan menurun.  Nilai kekerasan lapisan NiCoCrAlY pada substrat baja karbon adalah sebesar 349,95 HV, nikel krom sebesar 315,60 HV dan hastealloy sebesar 311,30 HV. Jarak dengan interface mempengaruhi pengukuran kekerasan. Semakin dekat dengan interface akan semakin menurun nilai kekerasaannya. Hal ini dipengaruhi oleh daerah interdifusi elemen pelapis sehingga mempengaruhi kekuatan mekaniknya.

Evolutions of Microstructure for Multilayered Al-Mg Alloy Composites by Accumulation Roll Bonding (ARB) Process

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao
Keyword(s):  
Multilayer Structure ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Fine Grained ◽  
Hardness Tester ◽  
Average Grain Size ◽  
Evolution Of Microstructure

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.

scholarly journals Influence of the resistive-pulse welding parameters of nickel super-alloys on selected properties of the connection

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1060-1062
Author(s):  
Sławomir Spadło ◽  
Wojciech Depczyński ◽  
Piotr Młynarczyk ◽  
Tadeusz Gajewski ◽  
Jarosław Dąbrowa
Keyword(s):  
Optical Microscope ◽  
Mechanical Tests ◽  
Welding Parameters ◽  
Thin Sheets ◽  
Micro Hardness ◽  
Hastelloy X ◽  
Haynes 230 ◽  
Hardness Tester ◽  
Resistive Pulse ◽  
Pulse Welding

Microstructure and mechanical tests of welds of thin sheets made from nickel-based super-alloys (Haynes 230 and Hastelloy X) were presented. The welds were made using the resistive-pulse micro-welding method using the WS 7000S device. The micro-hardness of the joints was measured with a Matsuzawa Vickers MX 100 hardness tester at 100 G (0.98 N). Metallographic observations of the prepared micro-sections were performed using the Nikon Eclipse MA200 optical microscope at various magnifications. The metallographic microstructure studies were supplemented by linear analysis of the chemical composition, for which the OXFORD X-MAX electron microscope was applied.

scholarly journals PERUBAHAN NILAI KEKERASAN DAN KONDUKTIVITAS LISTRIK ALUMINIUM AKIBAT PROSES EQUAL CHANNEL ANGULAR PRESSING (ECAP)

ROTASI ◽  
2014 ◽  
Vol 16 (4) ◽  
pp. 41
Author(s):  
Rusnaldy Rusnaldy ◽  
Norman Iskandar ◽  
Muhammad Khairul Rais ◽  
Wisnu Tri Erlangga
Keyword(s):  
Electrical Conductivity ◽  
Plastic Deformation ◽  
Equal Channel Angular Pressing ◽  
Hardness Test ◽  
Hardness Measurement ◽  
Optical Microscope ◽  
Pure Aluminium ◽  
Angular Pressing ◽  
Ecap Process ◽  
Number Of Passes

In current study, Equal Channel Angular Pressing (ECAP) process was applied to pure aluminium rod. The effect of the number of passes on hardness and electrical conductivity ECAP samples was investigated. The dimensions of ECAP die for 12 mmm diameter workpieces are designed with intersect angle of 120o. The experiments were carried out by using samples cut from an ingot and a rod and machined to a size of 12 mm in diameter and 50 mm in length. The workpiece was pressed into the ECAP die up to 7 passes at room temperature.After deformation, all samples were subjected to a hardness test, an electrical conductivity test and for optical microscope study. The hardness measurement of the ECAP samples suggested that enhanced hardness would be obtained by repeating ECAP process.Increasing the electrical conductivity of the ECAP samples indicatesthat there is no dislocation formation due to increasing plastic deformation in ECAP process

Experimental Investigation on the Nickel-Based Metal Components Fabricated by Laser Cladding

2008 ◽  
Vol 375-376 ◽  
pp. 338-342 ◽  
Author(s):  
Xia Ji ◽  
Jian Zhong Zhou ◽  
Hua Feng Guo ◽  
Da Peng Xu
Keyword(s):  
Experimental Investigation ◽  
Laser Cladding ◽  
Orthogonal Design ◽  
Hardness Measurement ◽  
Processing Parameters ◽  
Process Conditions ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Cladding Layer ◽  
Powder Feed

This paper presents an experimental investigation on the metal components fabricated by laser cladding. In the present study, two process of laser cladding were conducted, that is pre-placed powder cladding and coaxial powder-feed cladding. The effect of processing parameters was studied and optimum set of parameters for the superior surface quality was established by employing the orthogonal design. The fabricated components were subjected to metallographic examinations and micro-hardness measurement. Results indicated that the microstructure of coaxial cladding components was finer than pre-placed powder cladding components. The micro-hardness of the fabricated specimen along and vertical the scanning direction were measured using a HVS-1000 micro-hardness tester with a 200 g applied load. Analysis of the physical properties provided further evidence of differences in micro-hardness produced by different process conditions, and the average micro-hardness value of pre-placed power cladding layer was lower than the coaxial powder-feed cladding layer.

scholarly journals Micro-hardness measurement of photopolymer in stereolithography.

1997 ◽  
Vol 10 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Yi XU ◽  
Masato IMAMURA ◽  
Takeo NAKAGAWA
Keyword(s):  
Hardness Measurement ◽  
Micro Hardness

The Research on the Microstructure and Property of Gear with Sinter Powder Material

2010 ◽  
Vol 37-38 ◽  
pp. 1558-1560 ◽  
Author(s):  
Bai Yang Lou ◽  
Fang Liang Dong ◽  
Bin Xu
Keyword(s):  
Powder Material ◽  
Base Material ◽  
Residual Austenite ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Tempered Martensite ◽  
Common Part ◽  
Energy Spectrometer ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

Gear is a widely used common part of machinery, which is of good lubricate property and low materials consumption when it is made of sinter powder material. In this paper, the chemical composition, microstructure and property of sintered gear were investigated with optical microscope, scan electronic microscope, micro hardness meter and X-diffraction energy spectrometer. The results show that the microstructure of the gear includes of tempered martensite, carbide, residual austenite and a small quantity of cavity. The distribution of iron element is even. The copper and nickel distribute unevenly and cover around the surface of carbide in gear material which makes different property of covered layer itself between carbide and base material. The existing of covered layer and weak grain-boundary strength are main reason for gear brittle fracture. The gear’s toughness can be increased by optimizing sintering technology and heat treatment.

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