scholarly journals Development of Fe-11Al-xMN alloy steel on cryogenic temperatures

2021 ◽  
Vol 5 (12(113)) ◽  
pp. 60-68
Author(s):  
Ratna Kartikasari ◽  
Adi Subardi ◽  
Andy Erwin Wijaya
Keyword(s):  
Corrosion Resistance ◽  
Cryogenic Temperature ◽  
Temperature Treatment ◽  
Cell Polarization ◽  
304 Stainless Steel ◽  
Cryogenic Temperatures ◽  
Fracture Elongation ◽  
Before And After ◽  
Cryogenic Process ◽  
The Impact

This research is focused on increasing the reliability of Fe-11Al-Mn by combining the properties of Mn and the superiority of Fe-Al-C under cryogenic temperature. Three Fe-11Al-Mn alloys with compositions of 15 wt % Mn (F15), 20 wt % Mn (F20), and 25 wt % Mn (F25) were investigated. The cryogenic process uses liquid nitrogen in a temperature range of 0–196 °C. Hardness testing using the Vickers method and SEM was used to analyze the microstructure. X-ray diffraction (XRD) testing was conducted to ensure the Fe-11Al-Mn alloy phase and corrosion testing was carried out using the three-electrode cell polarization method. With the addition of Mn, the Vickers hardness of the Fe-11Al-Mn alloy decreased from 331.50 VHN at 15 wt % to 297.91 VHN at 25 wt %. The value of tensile strength and fracture elongation values were 742.21 MPa, 35.3 % EI; 789.03 MPa, 41.2 % EI; and 894.42 MPa, 50.2 % EI, for F15, F20, and F25, respectively. An important factor for improving the performance of cryogenic materials is the impact mechanism. The resulting impact toughness increased by 2.85 J/mm2 to 3.30 J/mm2 for F.15 and F25, respectively. The addition of the element Mn increases the corrosion resistance of the Fe-11Al-Mn alloy. The lowest corrosion rate occurs at 25 % wt Mn to 0.016 mm/year. Based on the results, the F25 alloy has the highest mechanical and corrosion resistance of the three types of alloys equivalent to SS 304 stainless steel. The microstructure of Fe-11Al-Mn alloy was similar between before and after cryogenic temperature treatment, this condition showed that the microstructure did not change during the process. From the overall results, the Fa-11Al-Mn alloy is a promising candidate for material applications working at cryogenic temperatures by optimizing the Mn content

The Impact of Seawater Corrosion on Friction Torque of Bearing Deputy Campaign

2011 ◽  
Vol 121-126 ◽  
pp. 2965-2968
Author(s):  
Cheng Zhao ◽  
Kun Luo ◽  
Chang Yin Gao
Keyword(s):  
Finite Element ◽  
Corrosion Resistance ◽  
Stress State ◽  
Similarity Theory ◽  
Friction Torque ◽  
Seawater Corrosion ◽  
Load Calculation ◽  
Before And After ◽  
The Impact

According to the stress state and corrosion resistance of bearing deputy campaigns,NO.5 bearing deputy campaign was selected as research subject.The work including design, processing, finite element load calculation, friction torque before and after corrosion of bearing deputy campaign samples were carried out according to similarity theory. Friction torque calculations of bearing deputy campaign before and after corrosion were 2.9×106N•mm and 3.2×106N•mm respectively. Compared with the friction torque before corrosion,the friction torque of bearing deputy campaign was increased by 10.4% because of seawater corrosion.

scholarly journals Development of Fe-5Al-1C alloys for grinding ball

2021 ◽  
Vol 1 (12 (109)) ◽  
pp. 29-35
Author(s):  
Ratna Kartikasari ◽  
Adi Subardi ◽  
Andy Erwin Wijaya
Keyword(s):  
Corrosion Resistance ◽  
Wear Test ◽  
Alloy System ◽  
Cell Polarization ◽  
Dry Sliding Wear ◽  
Fracture Elongation ◽  
System A ◽  
Electrode Cell ◽  
Pin On Disc ◽  
Mn Content

Our object of research is to combine the properties of Mn and the advantages of Fe-Al-C to improve the performance of grinding ball materials. Three Fe-5Al-1C alloys with compositions of 15 wt% Mn (FAM15), 20 wt% Mn (FAM20), and 25 wt% Mn (FAM25) were investigated. Argon gas was used to assist the removal of dissolved oxygen and to control the formation of metal oxides during Fe-Al-Mn-C (FAMC) fabrication. Microstructure analysis was conducted using scanning electron microscopy, and the Vickers microhardness tester was used to evaluate hardness. To guarantee the Fe-5Al-1C-Mn alloy phase, X-ray diffraction (XRD) test was performed. The EDS test was carried out to show the composition at different points and to observe the presence of several phases in the FAMC alloy system. A pin-on-disc method was employed for a dry sliding wear test, and corrosion testing was performed using the three-electrode cell polarization method. With the addition of Mn, the Vickers hardness of the FAMC alloy raised from 194.4 VHN at 15 wt% to 265 VHN at 25 wt%. The tensile strength and fracture elongation values were 424.69 MPa, 27.16 % EI; 434.72 MPa, 33.6 % EI; and 485.71 MPa, 38.48 % EI for FAM15, FAM20, and FAM25, respectively. A crucial factor for increasing the performance of grinding ball is the wear mechanism. The wear rate results for FAM25 show a decline of more than 57 % compared to FAM15 due to an increase in the hard intermetallic area. The addition of Mn elements increased the corrosion resistance of the FAMC alloys; the lowest corrosion rate occurred at 25 wt% Mn content at up to 0.036 mm/yr. According to the experimental results, the FAM25 alloys have the highest mechanical and corrosion resistance of the three types of alloys. The FAMC alloy is a promising candidate for application as a material for grinding balls by optimizing the Mn content

scholarly journals Experimental Study on Submerged High-Pressure Jet and Parameter Optimization for Cavitation Peening

Mechanika ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 346-353
Author(s):  
Yongfei YANG ◽  
Wei LI ◽  
Weidong SHI ◽  
Chuan WANG ◽  
Wenquan ZHANG
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Surface Profile ◽  
304 Stainless Steel ◽  
Nozzle Geometry ◽  
High Speed Photography ◽  
Sem Images ◽  
Before And After ◽  
The Impact ◽  
Divergent Angle

To increase the performance of high pressure submerged cavitation jet that has been used for cavitation peening, the effect of stand-off distance and the nozzle geometry on the impact capacity is investigated and optimized. High speed photography of the cavitation bubble clouds taken to reveal the unsteady characteristics of the cavitating jet. The impact ability of the jet with different nozzles and standoff distance is tested using Al 1060 at first, and the optimized jet is used then for cavitation peening on 304 stainless steel. The surface profile as well as the grain structures before and after peening using different nozzles are observed from SEM images. It is found that, the divergent angle of the nozzle has a great effect on the impact capability of the submerged high-pressure jet, which is important for improving the peening efficiency. In the nozzles with divergent angle 40°, 60° and 80°, the 60° nozzle shows the best performance. After peening, grain cells under the metal surface are changed and a twin layer is formed. The current research reveals the transient characteristics of the submerged cavitation jet and main factors that affect its impact rate, which provides guide for the nozzle design and application for the high-pressure cavitation jet peening.

Corrosion resistance of hoisting ropes

2020 ◽  
Vol 62 (12) ◽  
pp. 1173-1180
Author(s):  
Haşim Fırat Karasu ◽  
Mine Demirsoy
Keyword(s):  
Corrosion Resistance ◽  
Aging Process ◽  
Steel Wire ◽  
Accelerated Aging ◽  
Electrochemical Test ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Different Types ◽  
Before And After ◽  
The Impact

Abstract In this study, the goal is to determine the types of steel rope best used in environments such as harbors and on ships, by examining the behavior of different types of steel wire hoisting ropes used in cranes with respect to corrosion. Initially, hemp and steel wire core ropes were taken from 6 × 19 Standard, 8 × 19 Seale and 6 × 36 Warrington Seale rope groups that have the same diameter. Corrosion resistance was compared in these ropes through the application of three methods. According to the first method, corrosion resistance was examined via change in material mass. For this purpose, ropes were subjected to an accelerated aging test in an aging test cabin in accordance with ASTM B117 standard for one month for each aging process. 3 different 30-day processes were followed with 24-hour cycles. Corrosion exposure rates differed for each process. After going through the aging process, the damage suffered by the ropes was determined via visual inspection and the impact left by corrosion was evaluated by examining the mass changes seen in the ropes before and after aging for each process. The Tafel extrapolation, which is an electrochemical test, was applied in the second method. Ecorr and Icorr values of the ropes as well as their corrosion rates were determined and compared. Corrosion behavior was investigated in the third method through the application of mechanical experiments on aged steel ropes. In conclusion, corrosion resistant hoisting ropes were identified by comparing the results attained from the three methods.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

ANALISIS PENGARUH PEMBANGUNAN JALAN LAYANG JANTI TERHADAP PERKEMBANGAN TATA RUANG KAWASAN JANTI STUDI KASUS : KAWASAN JANTI, DESA CATURTUNGGAL, KABUPATEN SLEMAN, D. I. YOGYAKARTA

2017 ◽  
Vol 11 (3) ◽  
pp. 255
Author(s):  
Jeky El Boru
Keyword(s):  
Road Network ◽  
Open Space ◽  
Qualitative Description ◽  
Analysis Method ◽  
Open Spaces ◽  
The Road ◽  
Before And After ◽  
Linkage Method ◽  
The Impact ◽  
Parking Place

Abstract: This research aims to analyze the impact of Janti Flyover Construction toward the growth of layout at Janti Urban Area, including structured space, open space, and linkage. Method used for data collecting are observation, air photograph monitoring, and interview, whereas the analysis method is qualitative description, which is the superimposed method of two layers, that are the layout condition before and after flyover construction. The result shows that the impact of Janti Flyover construction can be seen on building mass (solid), the increasing number of open spaces, including the road network, parking place, and park, whereas the relation between spaces, visually and structurally, can be seen on the growth of buildings which have new shapes and styles, therefore the performance of the overall building does not have a proportional shape. Considering Janti Street at the collective relation, its role is getting stronger as the main frame road network.Keywords: Flyover construction, layout changing, Janti AreaAbstrak: Penelitian ini bertujuan untuk menganalisis pengaruh pembangunan Jalan Layang Janti terhadap perkembangan tata ruang Kawasan Janti, meliputi ruang terbangun, ruang terbuka, serta hubungan antar ruang (“linkage”). Metode pengumpulan data dilakukan melalui observasi, pengamatan foto udara, dan wawancara; sedangkan metode analisis melalui deskripsi secara kualitatif yang berupa “superimposed method” dari dua lapisan kondisi lahan, yakni kondisi tata ruang sebelum dan sesudah pembangunan jalan layang. Hasil penelitian menunjukkan bahwa pengaruh pembangunan Jalan Layang Janti terdapat pada massa bangunan (“solid”), pertambahan ruang terbuka yang berupa jaringan jalan, parkir, dan taman; sedangkan pada hubungan antar ruang ̶ secara visual dan struktural ̶ yakni tumbuhnya bangunan dengan bentuk dan gaya baru, sehingga bentuk tampilan bangunan secara keseluruhan tidak proporsional. Pada hubungan kolektif, Jalan Janti semakin kuat perannya sebagai kerangka utama jaringan jalan.Kata kunci : Pembangunan jalan layang, tata ruang, Kawasan Janti

Impact of merger on efficiency and productivity : a case study of commercial banks in Malaysia

1970 ◽  
Vol 5 (1) ◽  
pp. 77
Author(s):  
Mahadzir Ismail ◽  
Saliza Sulaiman ◽  
Hasni Abdul Rahim ◽  
Nordiana Nordin
Keyword(s):  
Efficiency Score ◽  
Malmquist Productivity Index ◽  
Productivity Index ◽  
Data Envelopment ◽  
Master Plan ◽  
Before And After ◽  
Domestic Banks ◽  
The Impact ◽  
Efficiency And Productivity

The Financial Master Plan (2001- 2010) aims to enhance the capacity of banking industry so that higher effic iency and productivity can be reaped in the future. This study seeks to determine the impact of merger on the efficiency and productivity ofcommercial banks in Malaysia for the period 1995 until 2005. The study uses a non-parametric approach, nam ely DEA (data envelopment analysis?) to estimate the efficiency scores and to construct the Malmquist productivity index. To enable this estimation, three bank inputs and outputs are used. Amongst the findings are those banks exhibit higher efficiency score after the merger and thefo reign banks are more efficient than the local banks. Productivity of the banks is calculated in both periods, before and after the merger: The results show that, it is the local banks that have improved the most after the merger. The main source of productivity is technical change or innovation. The findings support the existing policy of having larger domestic banks in term of size.

THE EFFECT OF METACOGNITIVE INSTRUCTION ON MAXIMIZING EFL LEARNERS’ METACOGNITIVE AWARENESS IN LISTENING

2018 ◽  
Vol 7 (1) ◽  
pp. 8-17
Author(s):  
Mahsa Assadi
Keyword(s):  
Experimental Research ◽  
Listening Comprehension ◽  
Intervention Program ◽  
Metacognitive Awareness ◽  
Listening Test ◽  
Efl Learners ◽  
Metacognitive Instruction ◽  
Before And After ◽  
Comprehension Ability ◽  
The Impact

This study reports a pre-experimental research on the impact of metacognitive instruction on EFL learners’ metacognitive awareness and their listening performance. To obtain the goal of the study, a group of 30 Iranian intermediate EFL learners, including 14 males and 16 females, were selected randomly. Their ages range from 20 to 24. The participants took part in 16 weeks’ intervention program based on metacognitive pedagogical sequence consisted of five stages. The metacognitive awareness listening questionnaire (MALQ), and a listening test were also used to find changes in metacognitive awareness and listening performance before and after the treatment. The results of comparing pre and posttests scores revealed that metacognitive instruction raised the learners’ metacognitive awareness and helped them improve their listening comprehension ability.

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