فهرس المقالات Steels

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  1 - Improvement of Microstructure and Mechanical Properties of Manganese Steels by Adding Boron Alloying Element
  N. Arab
  Improvement of the mechanical properties and microstructures of industrial parts can improve working conditions, working life and reduce rejection rates and consequent, improve environmental effects of industrial developments. In this paper, the effect of Boron content أکثر

  Improvement of the mechanical properties and microstructures of industrial parts can improve working conditions, working life and reduce rejection rates and consequent, improve environmental effects of industrial developments. In this paper, the effect of Boron content in chemical composition ofManganese steel on improvement of microstructure and mechanical properties of manganese steels has been investigated. This improvement can reduce the consumption and rejection rate of castings and consequent environmental protection. The microstructure was investigated using optical, SEM and FESEM microscopy. In addition, mechanical tests such as tensile test, hardness and impact tests were performed on the samples. Microscopic investigations showed the presence of 0.007% Boron prevents of formation carbides in grain boundaries and also reduces the carbide sizes and cause uniform distribution. In the presence of Boron, annealing solution heat treatment, improve the morphology of carbides and modified it to spherical shape. The results of the research show that by increasing 0.007% Boron, fine and spherical carbides will form in austenitic microstructure of manganese steel which increase the hardness, toughness, tensile strength and modify carbide distribution and morphology in both heat treated and non-heat treated conditions. This results can improve casting operation time and rejection rates of castings in wear conditions as an environmental friendly material تفاصيل المقالة
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  2 - Effects of Shielding Gas on the Mechanical and Microstructural Properties of 409L Ferritic Stainless Steels during Gas Metal Arc Welding
  A. Feghhi A. Emamikhah Y. Bayat Asl
  The present study investigates the effects of type of shielding gas on the weld microstructure and mechanical properties of 409L ferritic stainless steel. For this purpose, Ar, Ar +20% He, Ar + 12% CO2, and Ar + 25% CO2 were used as shielding gases in gas metal arc weld أکثر

  The present study investigates the effects of type of shielding gas on the weld microstructure and mechanical properties of 409L ferritic stainless steel. For this purpose, Ar, Ar +20% He, Ar + 12% CO2, and Ar + 25% CO2 were used as shielding gases in gas metal arc welding (GMAW) of stainless steel. To evaluate the welds, non-destructive inspections of the specimens were followed by mechanical (hardness and tensile) tests while microstructural examinations of both the heat affected zone (HAZ) and the fusion zone were performed. Moreover, the phases produced were observed and identified by analyzing the specimens using SEM and EDS techniques. Results showed that specimens welded with Ar + 25% CO2 and Ar + 12% CO2 have the highest strength and hardness values in the fusion zone due to the formation of martensite around the ferrite grains. However, the enhancements observed in the mechanical properties of specimens welded with Ar and Ar +20% He were attributed to the reduced ferrite grain size and martensite content تفاصيل المقالة
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  3 - Weldability of Dissimilar Joint of AISI 304 to CK45 by GTAW Method
  A. Taherkhani Y. Shajari K. Mirzavand A. Mellatkhah Z. S. Seyedraoufi
  Joint of dissimilar steels is widely used in the chemical, food, oil, water and sewage industries. In the meantime, the joint of carbon steels to austenitic stainless steels is important with the GTAW welding process. In this paper, weldability of 304 stainless steel to أکثر

  Joint of dissimilar steels is widely used in the chemical, food, oil, water and sewage industries. In the meantime, the joint of carbon steels to austenitic stainless steels is important with the GTAW welding process. In this paper, weldability of 304 stainless steel to CK45 carbon steel by GTAW method according to the filler metal parameter has been investigated. Welding of the samples was performed via gas tungstenarc welding (GTAW)method using 3 types of ER308L, ER310, and ER316L metal filler. Tensile test was done to evaluate the joint weldability. The microstructure of the samples was also studied using OM and FE-SEM microscopes. In the tensile test, the welded sample with ER308L electrode was fractured from HAZ area close to Ck45 base metal. Microstructure investigations showed that the best structural quality in this joint is the achievement of the stable austenite with a low amount of ferrite when using ER308L metal filler, and the worst structure was related to the use of ER310L metal filler that completely austenite structure with crack in the weld metal area was created. The results of tensile test showed that the maximum yield strength and tensile strength is achieved 382 MPa and 675 MPa using ER308L metal filler, respectively. تفاصيل المقالة
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  4 - Effect of MIG Welding Parameters on Mechanical Properties of Dissimilar Weld Joints of AISI 202 and AISI 316 Steels
  Venkatratnam Dirisala KESAVA RAO V.V.S
  In the present work dissimilar joints of AISI 202 and AISI 316steels are produced using Metal Inert Gas (MIG) welding. Welding current, wire feed rate, flow rate of gas and edge included angle are considered as input parameters and tensile strength, Impact strength and أکثر

  In the present work dissimilar joints of AISI 202 and AISI 316steels are produced using Metal Inert Gas (MIG) welding. Welding current, wire feed rate, flow rate of gas and edge included angle are considered as input parameters and tensile strength, Impact strength and Maximum bending load are considered as output responses. Response Surface Method (RSM) is adopted using Central Composite Design (CCD) and 31 experiments were performed for 4 factors and 5 levels. Analysis of Variance (ANOVA) is carried out at 95% confidence level and coefficient of determination (R2) of 0.94 is obtained for all the output responses. Effect of welding parameters on output responses are studied by drawing main effect plots. Dominating parameters are identified using contour plots and surface plots are drawn to find the optimal solution. Optimal weld parameters are identified using Response optimizer. تفاصيل المقالة
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  5 - The Weldability Evaluation of Dissimilar Welds of AISI 347 Stainless Steel to ASTM A335 Low Alloy Steel by Gastungesten Arc Welding
  Iman Hajiannia Morteza Shamanian Masoud Kasiri
  In the present study, the Weldability and microstructure of dissimilar welds of AISI 347austenitic stainless steel to ASTM A335 low alloy steel was investigated. For this purpose, gas tungsten arc welding process and two filler metals including ERNICr-3 and ER309L were أکثر

  In the present study, the Weldability and microstructure of dissimilar welds of AISI 347austenitic stainless steel to ASTM A335 low alloy steel was investigated. For this purpose, gas tungsten arc welding process and two filler metals including ERNICr-3 and ER309L were used. After welding, the microstructure of the different zones of each joint, including weld metals, heat affected zone (HAZ) 1, inter face and unmixed zones (UMZ) 2 were evaluated by using optical microscopy. The scanning electron microscopy (SEM) 3 equipped to energy disperse spectrometry (EDS) 4 was used to investigate the precipitates, in order to predict the micro structure of the weld metal and transmission zone in dissimilar joints. In ERNiCr-3 weld metal, the solidification was observed as the completely austenitic and equiaxed dendrite5 which contains the precipitates of carbide complex, and also Niobium segregation was happened in the inter dendrite zones. 309L weld metal was observed as the primary ferrite with austenitic matrix and also microstructure was seen as skeletal ferrite morphology. The epitaxial growth was observed in interface between 347austenitic stainless steel and two filler metals and a narrow zone was observed in interface between A335low alloy steel and filler metals, and also the coarse grains occurred in HAZ zone of both weld metals. Finally, it can be denoted that for the joints between the AISI 347 austenitic stainless steel and A335low alloy steel, by the ERNICr-3 filler material provides the optimum qualities. تفاصيل المقالة
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  6 - Effect of Cold Rolling sequence on the Texture Development and Magnetic Loss of Grain Oriented Electrical Steels
  Mehdi Salari
  Electrical steels are important alloys widely used in electrical instruments. The magnetic properties and low core loss of grain oriented silicon steels are closely related to the sharpness of Goss texture ({110} ).The direction of is the softest direction for magnetism أکثر

  Electrical steels are important alloys widely used in electrical instruments. The magnetic properties and low core loss of grain oriented silicon steels are closely related to the sharpness of Goss texture ({110} ).The direction of is the softest direction for magnetism. In this work, the microstructure and dependence of orientation density along the major texture fibers on the applied cold rolling sequences in the CRGO samples were investigated. Variation of the hysteresis losses revealed that hysteresis losses were high for the specimen treated at higher secondary cold reduction. In this sample, the conditions for selective growth of Goss oriented grains are violated which leads to development of grains with random orientations almost equally. The results also indicated that the annealing of the cold rolled specimen at the higher first cold reduction and lower secondary reduction showed increase of the {110}texture component intensity and drastically decrease in hysteresis losses. تفاصيل المقالة
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  7 - Enhancement of hot forging die life using different methods
  صادق جعفرپور مسعود رضایی
  Forging dies at high temperatures are under contact pressure, variable mechanical loads and thermal shock, furthermore they should withstand wear and friction in a high level. So, in order to increase die life, the selection of die material, coating and hardness is esse أکثر

  Forging dies at high temperatures are under contact pressure, variable mechanical loads and thermal shock, furthermore they should withstand wear and friction in a high level. So, in order to increase die life, the selection of die material, coating and hardness is essential. In this review, various methods used for die life enhancement such as carbide coating, using the super alloy stellite 6 and etc. are presented in summary. تفاصيل المقالة
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  8 - ارزیابی خواص مکانیکی جوش های غیر مشابه فولاد زنگ نزن AISI 347 به فولاد کم آلیاژ ASTM A335
  ایمان حاجیان نیا
  دراین تحقیق، خواص مکانیکی جوش های غیرمشابه فولاد زنگ نزن آستنیتی 347 AISI به فولادکم آلیاژ ASTM A335 با استفاده از روش قوسی تنگستن-گاز با قطبیت منفی مورد بررسی قرار گرفت. بدین منظور از دو فلز پرکننده ERNiCr-3 و ER309L استفاده شد. برای بدست آوردن ساختار مطلوب و خواص مکان أکثر

  دراین تحقیق، خواص مکانیکی جوش های غیرمشابه فولاد زنگ نزن آستنیتی 347 AISI به فولادکم آلیاژ ASTM A335 با استفاده از روش قوسی تنگستن-گاز با قطبیت منفی مورد بررسی قرار گرفت. بدین منظور از دو فلز پرکننده ERNiCr-3 و ER309L استفاده شد. برای بدست آوردن ساختار مطلوب و خواص مکانیکی عالی در اتصالات مذکور، کنترل حرارت ورودی و عملیات حرارتی پیشگرم، از جمله پارامترهای موثر و قابل کنترل بود. ریزساختار فلزات پایه و فلزات جوش، با استفاده از میکروسکوپ نوری مورد ارزیابی قرار گرفت و برای بررسی سطوح شکست، از میکروسکوپ الکترونی روبشی1(SEM) استفاده شد. بررسی های ریزساختاری نشان داد که یک ساختار دو فازی شامل مناطق دندریتی و بین دندریتی در فلز جوش ERNiCr-3 با انجماد به صورت آستنیتی و در فلز جوش ER309L ساختاری شامل فریت اولیه استخوانی شکل در زمینه آستنیت مشاهده شد. همچنین خواص مکانیکی، شامل استحکام خمشی، استحکام کششی، مقاومت در برابر ضربه، سختی و نیز شکست نگاری نمونه‌ها بررسی شد. در آزمایش کشش تمامی نمونه‌ها، از منطقه 2HAZ فلز پایه فولادکم آلیاژ 335A و به صورت نرم دچار شکست شدند. تفاصيل المقالة