@article { author = {Dabir, Mohammad and Saffari, Hamed and Kermanpur, Ahmad}, title = {Effect of Tempering Treatment on Microstructure and Mechanical properties of the HSLA-100 steel}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {1-10}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.528128.1191}, abstract = {The high strength low alloy (HSLA) 100 steel has been widely used in various industries such as shipbuilding, military, oil and gas. An increase in yield strength with a reasonable toughness is highly demanding in this steel. In the present study, the quench-tempering heat treatment was investigated to improve mechanical properties of this steel. The samples were austenitized at 930 °C for 1 h followed by water quenching. They were then tempered in the temperature range of 410 and 710 °C for 1 to 4 h. Microstructures of the heat treated specimens were evaluated by optical and scanning electron microscopy, while mechanical properties measured by hardness, tensile, and toughness tests. The results showed that microstructural changes during tempering took place mainly after 650 °C, where the martensite laths and acicular ferrite transformed to polygonal ferrite. The yield and ultimate strengths were increased by increasing tempering temperature from 410 to 525 °C, beyond which both was dropped up to 710 °C. The maximum yield and ultimate strengths were obtained by tempering at either 525 °C for 1 h or 475 °C for 2 h. Increasing tempering temperature and duration both resulted in an increase in the absorbed impact energy.}, keywords = {HSLA 100 steel,Tempering heat treatment,Mechanical properties,Fractography}, title_fa = {تأثیر عملیات تمپر بر ریزساختار و خواص مکانیکی فولاد HSLA-100}, abstract_fa = {فولاد کم آلیاژ پراستحکام HSLA-100 در بسیاری از صنایع از جمله کشتی‌سازی، نظامی، و نفت و گاز کاربرد دارد. در این فولاد افزایش استحکام تسلیم همراه با چقرمگی نسبی مورد نیاز است. در کار حاضر، عملیات کوئنچ-تمپر برای بهبود خواص مکانیکی این فولاد مورد بررسی قرار گرفته است. نمونه‌ها در دمای C 930 به مدت یک ساعت آستنیته شده و در آب کوئنچ شدند. نمونه های کوئنچ شده سپس در محدوده دمائی 410 الی C 710 در بازه زمانی 1 تا 4 ساعت تمپر شدند. ریزساختار نمونه های عملیات حرارتی شده با میکروسکوپ نوری و الکترونی و خواص مکانیکی آنها توسط آزمون‌های سختی‌سنجی، کشش و ضربه بررسی شد. نتایج نشان داد که تغییرات ریزساختاری در بالاتر از دمای C 650 اتفاق می افتد؛ جایی که مارتنزیت لایه ای و فریت سوزنی به فریت چندوجهی تبدیل می شود. با افزایش دمای تمپر از C 410 تا C 525، استحکام تسلیم و استحکام کششی نهائی هر دو افزایش یافت، حال آنکه در بالاتر از C 525 تا دمای C 710 هر دو روند کاهشی نشان داشت. حداکثر استحکام تسلیم و استحکام کششی با تمپر در دمای C 525 به مدت یک ساعت و یا در دمای C 475 به مدت 2 ساعت بدست آمد. افزایش دما و زمان تمپر باعث بهبود انرژی ضربه شد.}, keywords_fa = {فولاد HSLA-100,عملیات حرارتی تمپر,خواص مکانیکی,شکست نکاری}, url = {https://journal.issiran.com/article_246287.html}, eprint = {https://journal.issiran.com/article_246287_cffa8da220ab1e728b36641d633de00b.pdf} } @article { author = {Lotfian, Najmeh and Nourbakhsh, Amirabbas and MacKenzie, Kenneth}, title = {Relationship between steel shell temperature and nano MgCr2O4 addition on steel snorkel life time in Ruhrstahl-Heraeus vacuum steel refining units}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {11-22}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.531468.1200}, abstract = {An investigation of the corrosion problems of the mag-chrome refractories used in the cylindrical component (snorkel) of Ruhrstahl-Heraeus (RH) vacuum degassing units is reported. The snorkel consists of a steel shell surrounded by a monolithic refractory and enclosing mag-chrome refractory bricks. Operational factors (degassing duration, time between heating cycles, number of heating cycles in a degassing sequence and the snorkel temperature) can overheat the steel shell and decrease the life of the snorkel. In the present study, the average temperature between the top and bottom of the steel shell was estimated by FDM (Finite Difference Method), indicating that thermal degradation due to creep will occur in the steel shell. In addition, the increasing number of hydrogen removal process during the degassing operation from the steel, the consumption of Fe-Si increased, producing more FeO and resulting in greater chemical corrosion of the refractory bricks. An investigation of these two mechanisms (thermal degradation and chemical corrosion) suggests that snorkel degradation could be mitigated by adjusting the number of daily heat sequences and cooling the steel shell, whereas the addition of MgCr2O4 nano additives to encourage spinel formation can be used to increase the hot modulus of rupture and increase the corrosion resistance.}, keywords = {snorkel,mag-chrome,Refractories,Corrosion,Thermal shock}, title_fa = {ارتباط بین دمای پوسته فولادی و افزودنی های نانو ساختار MgCr2O4 بر طول عمر پوسته فولادی درواحد RH}, abstract_fa = {}, keywords_fa = {اسنورکل,منیزیا-کرومیت,دیرگداز,خوردگی,شوک حرارتی}, url = {https://journal.issiran.com/article_246284.html}, eprint = {https://journal.issiran.com/article_246284_d4f37e6924428051b73b51c50d75fb9f.pdf} } @article { author = {Haghighat Khah, Saeid and Tavakoli, Hossein and Azadi, Mahboobeh}, title = {Effects of Addition of Waste Toner Particles on Tribological Properties of Ni-P Coatings Before and After Heat Treatment}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {23-32}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.530253.1197}, abstract = {This study investigated the tribological properties of Ni-P coatings produced by the electroless plating technique with various amounts of waste toner particles added to the plating bath. The properties were examined before and after a heat treatment process involving 60 minutes of heating at 400ºC. The impact of the concentration of toner particles in the plating bath on the properties and also the microstructure, phases, micro-hardness and wear mechanism and characteristics of the modified coatings were investigated. Field emission scanning electron microscopy (FESEM) images showed that toner particles were homogeneously distributed in the Ni-P matrix. The addition of 1 g/L of waste toner particles to the plating bath significantly increased the wear resistance of the coating and reduced its coefficient of friction (COF) to as low as 0.25. Although heat treatment increased the micro-hardness of all of the coatings, it did not lead to a significant improvement in the wear resistance of the toner-containing coating compared to the conventional coating. The presence of toner particles in the plating bath decreased the coating growth rate from 0.16 to 0.08 µm/min. Increasing the concentration of toner particles from 1 to 5 g/L decreased the toner content of the resulting Ni-P coatings, leading to reduced micro-hardness and consequently increased wear rate of the produced composite coatings.}, keywords = {Ni-P Coatings,Toner,Electroless,Tribological Property,Wear}, title_fa = {اثر اضافه کردن ذرات تونر دورریز بر خواص تریبولوژی پوشش Ni-Pقبل و بعد از عملیات حرارتی}, abstract_fa = {}, keywords_fa = {}, url = {https://journal.issiran.com/article_246288.html}, eprint = {https://journal.issiran.com/article_246288_b9c5a9cb082b722ecc375c9e2817ede7.pdf} } @article { author = {Assa, Farnaz and Sharifi, Leila and Mirhosseini, Seyed Hossein and Ajamein, Hossein and Etemad, Arash}, title = {Effect of zirconia addition on the properties of dolomite magnesia refractories used in steel industries}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {33-43}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.535306.1204}, abstract = {In this study, the influence of the zirconia addition on the properties and microstructure of alkali magnesia refractories without chrome band spinels was investigated. For this purpose, a primary formula based on magnesia and alumina to form spinel was considered, and different amounts of zirconia were added to achieve various samples. After thermal treatment at 1500 ̊C and 1600 ̊C, the physical and mechanical properties of fabricated samples such as density, apparent porosity, cold compressive and bending strength, refractoriness under load, and warm modulus of rupture according to ASTM were evaluated. The physical and mechanical properties of zirconia contained samples revealed that the addition of zirconia led to the formation of zirconate-based phases like magnesium zirconate, and calcium zirconate. This phase can be expanded by the thermal stresses due to its thermal mismatch with the phases of the field and improved the mechanical properties by creating microcracks in the structure. Addition of 2% by weight of zirconia increased the density from 2.8 g/cm3 to 2.95 g/cm3 at 1600 °C. Compressive strength also increased from 315 kg/cm2 to 550 kg/cm2 and flexural strength from 35 kg/cm2 to 65 kg/cm2.}, keywords = {Refractories material,Magnesia alkaline brick,Zirconia,Spinel phase}, title_fa = {تاثیر افزودن زیرکون بر خواص نسوز دولومیت منیزیم مورد استفاده در صنایع فولاد}, abstract_fa = {}, keywords_fa = {}, url = {https://journal.issiran.com/article_246285.html}, eprint = {https://journal.issiran.com/article_246285_32d0404a9c8c8940a1fe08c749b62e12.pdf} } @article { author = {Moosavi nezhad, Mohsen and Hemmati, Mohammad Hosain}, title = {Evaluation of Reduction of Electric Arc Furnace (EAF) Dust Using Volatile Matter of Non-Coking Coal}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {44-55}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.533053.1201}, abstract = {In this research, the reduction of iron and zinc oxides of Electric Arc Furnace (EAF) dust using volatile matter of non-coking coal was investigated. Reduction was performed by two types of coals at three different heating rates in the temperature range of 25-950 ℃. The weight percentages of volatile matters in types 1 and 2 of the coal were 37% and 24%, respectively. Factsage 6.1 software was used to determine thermodynamic feasibility of the reduction process. The chemical composition of the dust was determined by ICP method, before and after the reduction process. The results of thermodynamic simulations show that decreasing the heating rate of the coal from 18.4 to 13.5 ℃/min leads to complete reduction of iron and zinc oxides in both types of coals. A higher amounts of volatile matter in coal 1 has caused higher amounts of reduction degree. Experiments show that at high heating rates of the coal, only small fraction of iron and zinc oxides are reduced. At lower heating rates, reduction degree increases and the results of experiments are closer to the those of thermodynamic simulations. The best results were obtained at a heating rate of 13.5 ℃/min for coal 1. Under these conditions, reduction of iron and zinc oxides takes place by 75% and 89%, respectively. In addition, the weight percentage of iron in the dust has increased from 31% to 46% that provides the possibility of dust recharge into the furnace.}, keywords = {Electric Arc Furnace Dust,Non-coking coal,volatile matter,Coal Heating Rate,Reduction}, title_fa = {ارزیابی احیای غبار کوره قوس الکتریکی به کمک مواد فرار ذغال سنگ کک نشو}, abstract_fa = {در این پژوهش، احیای اکسیدهای آهن و روی در غبار کوره های قوس الکتریکی فولاد سازی توسط مواد فرار ذغال سنگ های کک نشو مورد بررسی قرار گرفته است. احیا توسط دو نوع زغال در سه سرعت متفاوت گرمایش ذغال در بازه دمایی 950-25 درجه سلسیوس انجام شده است. ذغال نوع1 و نوع 2 به ترتیب دارای 37% و 24% وزنی مواد فرار بوده اند. از نرم افزار Factsage 6.1 به منظور بررسی امکان پذیری ترمودینامیکی فرایند احیاء استفاده شده است. ترکیب شیمیایی غبار قبل و بعد از فرایند احیاء، توسط روش ICP تعیین شده است. نتایج شبیه سازی های ترمودینامیکی نشان میدهد، با کاهش سرعت گرمایش ذغال از 18.4 به 13.5 درجه سلسیوس بر دقیقه امکان احیای کامل اکسیدهای آهن و روی در هر دو نوع ذغال به وجود می آید. ذغال نوع 1 به دلیل بالاتر بودن میزان مواد فرار، مقادیر بالاتری از درجه احیاء را سبب شده است. آزمایشات نشان می‌دهد در سرعت های بالای گرمایش ذغال، تنها بخش اندکی از اکسیدهای آهن و روی احیاء می شوند. در سرعت های پایین تر میزان احیاء افزایش یافته و نتایج آزمایشات به نتایج شبیه سازی های ترمودینامیکی نزدیک تر شده است. بهترین نتایج در سرعت گرمایش 13.5 درجه بر دقیقه و برای ذغال 1 پدید آمده است. در این شرایط احیای اکسیدهای آهن و روی به ترتیب به میزان 75% و 89% انجام شده است. همچنین درصد آهن در غبار از 31% به 46% وزنی افزایش یافته و امکان شارژ مجدد آن به درون کوره فراهم شده است.}, keywords_fa = {غبار کوره قوس الکتریکی,ذغال سنگ کک نشو,مواد فرار,نرخ گرمایش ذغال,احیا}, url = {https://journal.issiran.com/article_246283.html}, eprint = {https://journal.issiran.com/article_246283_8dca2957bd8b55832d911da9090a1976.pdf} } @article { author = {Obeydavi, Ali and Shafyei, Hassan and Tayyebi, Abdollah}, title = {Investigation the effect of sol-gel method approach on microstructural of NiO/MgAl2O4 nanocatalysts applicable for steel industry: modified sol-gel method and sol-gel citrate}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {56-63}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.531121.1199}, abstract = {Nickel-based catalysts have been widely used in the important reaction for producing hydrogen and synthesis gas from methane reforming processes, which use for producing of steel. The aim of this study was to investigate the effect of the sol-gel method approach on the synthesis of NiO/MgAl2O4 nano catalysts through the modified sol-gel and sol-gel citrate methods. Powders are characterized using XRD, SEM-EDS, TEM, and BET-BJH. The results showed that the use of two different sol-gel approaches caused changes in microstructural properties. Nano catalysts prepared by the modified sol-gel method had smaller crystalline size, smaller particle size, larger porosity and larger specific surface area than the prepared nano catalysts by the sol-gel citrate method. The shape of the nano catalyst particles prepared by the two sol-gel methods was spherical, except that the shape and size of the particles were more homogeneous in the prepared nano catalyst by the modified sol-gel method.}, keywords = {Modified sol-gel method,Sol-gel citrate,Microstructural,Nano catalyst,NiO/MgAl2O4}, title_fa = {بررسی اثر روش سل-ژل بر ریزساختار نانوکاتالیست های NiO/MgAl2O4 قابل استفاده در صنعت فولاد: روش اصلاح سل-ژل و ژل سیترات}, abstract_fa = {}, keywords_fa = {}, url = {https://journal.issiran.com/article_246286.html}, eprint = {https://journal.issiran.com/article_246286_b8db950fbe89f6d8f8d7adab5986f072.pdf} } @article { author = {Ghaderi, Fateme and Kheirandish, Shahram}, title = {The Effect of Heat Treatment and Cold-Work on Precipitation and Recrystallization of BioDur108 HNS Steel}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {64-73}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.535405.1203}, abstract = {ABSTRACTHNS (High Nitrogen Austenitic Stainless Steel) steels are attractive materials due to their unique combination of outstanding mechanical and corrosion resistance properties in medical and industrial applications. However, despite the excellent traits, brittle precipitates formation during aging would subvert the structure. Many studies performed on the aging reactions and the nature of deposits. This paper focuses on the effect of heat treatment and cold-work on precipitation and recrystallization behavior in the sensitive deposition zone of BioDur108 HNS. For this purpose, Samples of high nitrogen austenitic stainless steel with cold-work values of 0, 40 and, 60% were subjected to isothermal annealing at 4 temperatures of 850, 900, 950 and 1000 ° C, a constant time of 30 minutes and, followed by water quenching. Microstructural characterization was carried out via optical microscopy and, EDS tests. Vickers Hardness was carried out. In all cold-worked samples, recrystallization occurs before deposition. Sensitive deposition temperature is 950, 900 and 850°C, respectively for 0, 40, and 60% amount of cold-work. Increasing the percentage of cold-work causes the transfer of sensitive deposition temperature to lower. No carbide is formed and, the precipitates, during annealing in cold-worked samples, are the predominant Cr2N and Sigma phase. The main cause of the hardness increase is Cr2N deposition.}, keywords = {HNS Steel,Precipitation,Sensitive Deposition Temperatures,Solution annealing,Cold- work,Cr2N}, title_fa = {تاثیر عملیات حرارتی و کار سرد بر رسوبگذاری و تبلور مجدد فولاد آستنیتی پر نیتروژن BioDur108}, abstract_fa = {هدف از پروژه حاضر بررسی تاثیر عملیات حرارتی و کار سرد بر رسوبگذاری و تبلور مجدد فولاد زنگ نزن آستنیتی پر نیتروژن BioDur108 است. به این منظور نمونه های زنگ نزن آستنیتی پر نیتروژن با مقادیر کار سرد 0، 40 و 60% تحت عملیات آنیل محلولی هم دما در 4 دمای 850, 900, 950 وC° 1000به مدت زمان 30 دقیقه قرار گرفتند و سپس در آب سریع سرد شدند. مطالعات ریز ساختاری با میکروسکوپ نوری انجام گرفت. تست سختی ویکرز وآزمون EDS انجام شد. در تمام نمونه های کار سرد شده تبلور مجدد قبل از رسوبگذاری اتفاق افتاده است. دمای حساس رسوبگذاری برای مقادیر کار سرد 0، 40 و 60% به ترتیب ,950، 900 و °C 850 است. افزایش کار سرد سبب انتقال دمای حساس رسوبگذاری به دمای پایین ترشده است.هیچ گونه کاربید تشکیل نشده است. رسوبات تشکیل شده حین عملیات آنیل محلولی برای نمونه های کار سرد شده Cr2N و فاز سیگما هستند که رسوب غالب را Cr2N تشکیل می دهد. در نمونه 0% کار سرد تنها Cr2N تشکیل شده است. علت اصلی افزایش سختی تشکیل رسوبات Cr2N می باشد.}, keywords_fa = {HNS,دمای حساس رسوبگذاری,آنیل محلولی,کارسرد,Cr2N,تبلور مجدد}, url = {https://journal.issiran.com/article_248313.html}, eprint = {https://journal.issiran.com/article_248313_45b042a664c59a4e2ec2c8d5c3ef2178.pdf} } @article { author = {Foadian, Elham and Mokmeli, Mohammad and Sheibani, Saeed}, title = {Optimization of Blast Furnace through Reducing Coke Consumption and CO2 Emission using HSC Software}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {74-82}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.540469.1210}, abstract = {In this paper, a comprehensive evaluation of the charged materials, energy consumption and CO2 emissions of blast furnace (BF) is done by relating the operating data from the Esfahan steel company (ESCO) with the established static process models. The mass and energy balance calculations were performed using the HSC software. This model is capable of predicting 16 independent variables of the 150 total variables at the same time. The model was verified by comparing the results with the ESCO BF No. 3 off gas, slag and dust composition and were found in 8% deviation from the operating data. The model indicated that increasing the hot air blast temperature and CH4 injection, reducing coke ash level and slag volume in the product improved the plant productivity. Compared with a convectional BF, the results of optimization showed that the energy consumption, CO2 emission and coke consumption were reduced by 3% (~183 Gj/THM), 16% (~0.56 kg/THM) and 15% (~79.5 kg/THM), respectively. The energy efficiency was calculated at 81.84% and was increased by about 5% in the optimizing conditions.}, keywords = {blast furnace,Mass and Energy Balance,HSC Software,CO2 emission,energy consumption}, title_fa = {بهینه سازی کوره بلند از طریق کاهش مصرف کک و انتشار CO2 با استفاده از نرم افزار HSC}, abstract_fa = {}, keywords_fa = {}, url = {https://journal.issiran.com/article_248315.html}, eprint = {https://journal.issiran.com/article_248315_a747224a158ebf704cda75d138c2e71e.pdf} } @article { author = {Ashtari, Pooria and Parvini Ahmadi, N. and Yazdani, Sasan}, title = {Wear behavior of laser cladded Ni based-WC-La2O3 hybrid composite coating on H13-Steel at elevated and ambient temperatures}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {83-97}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.536948.1205}, abstract = {Hybrid composite coatings show obvious advantages over single composite coatings due to their multipurpose applications. Furthermore, nickel-based alloy matrix composite coatings are extensively used in corrosive, wear and fatigue environments because of their good wear and corrosion resistance. In this study, NiCoCrAl/tungsten carbide/1-4 wt% lanthanum oxide composite coatings are deposited on H13 hot work tool steel by laser cladding. The wear resistance of the coatings is evaluated in sliding against alumina ball both at room temperature and 700 °C. The results indicate that the wear rate of the coatings decreases at room temperature by adding 1-3 wt% lanthanum oxide (72.55×10-6 mm3 N-1 m-1 for NiCoCrAl/tungsten carbide/2 wt% lanthanum oxide). Also, the friction coefficient decreases at this level of lanthanum oxide and for the samples with 2 and 3 wt% lanthanum oxide the steady stage of wear begins earlier than others. At the high temperature of 700 °C, the presence of lanthanum oxide has changed the wear mechanism from adhesive to abrasive and improved the wear performance of the coatings. At higher amounts of lanthanum oxide, debris removals is observed on the coatings where it resulted in the three-body and severe wear.}, keywords = {wear behavior,Laser cladding,Hybrid composite coating,lanthanum oxide,H13 tool steel}, title_fa = {رفتار سایش پوشش کامپوزیت هیبریدی نیکل با روکش لیزری WC-La2O3 بر روی فولاد H13 در دمای بالا و محیط}, abstract_fa = {}, keywords_fa = {}, url = {https://journal.issiran.com/article_248314.html}, eprint = {https://journal.issiran.com/article_248314_a55d26f1d38202a76cc84af8ddcba06e.pdf} } @article { author = {Omidi, Zahra and Farazmand, Hassan and Anvari, Ebrahim and Arman, Seyed Aziz}, title = {Investigating the impact of exchange rate and oil price fluctuations on Iran’s steel exports to China with sanctions in focus: A wavelet and multivariate-GARCH approach}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {98-105}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.540392.1209}, abstract = {Considering Iran's potential in steel production and exports, attention to its exports contributes to reducing the country’s dependence on oil revenues. Hence, the purpose of this study is to investigate the effect of exchange rate and oil prices on Iran’s steel exports to China in the period between February 2008 and March 2019 using the wavelet and multivariate-GARCH approaches. The results of the wavelet model showed that increasing in sanctions in the early 2010s and their intensification during 2018 and 2019 has intensified the impact of exchange rate on Iran's steel exports to China. Also, during the period 2013 to 2015, with the prolongation of the negotiation process and changes in world oil prices, the correlation between world oil prices and Iran's steel exports to China has intensified in the long run. The results of multivariate GARCH show that the correlation between the real exchange rate and Iran's steel exports to China has been negative for most of the period. Moreover, the correlation between the real exchange rate and oil prices has been positive for most of the period under study. Therefore, it can be said that steel is one of Iran's export commodities which increases its non-oil export revenues as oil prices and revenues increase.}, keywords = {Exports,Steel,Iran,Wavelet,Multivariate-GARCH}, title_fa = {بررسی رابطه نرخ ارز و قیمت نفت بر صادرات فولاد ایران به چین با تاکید بر تحریم‌ها: رویکرد موجک و گارچ چند متغیره}, abstract_fa = {با توجه به پتانسیل کشور در تولید و صادرات فولاد، توجه به صادرات آن در کاهش وابستگی به درآمدهای نفتی مفید است. از این‌رو، هدف این مقاله بررسی رابطه نرخ ارز و قیمت نفت بر صادرات فولاد ایران به چین در بازه زمانی1387:11 تا 1398:12 با استفاده از رویکرد موجک و گارچ چند متغیره است. نتایج مدل موجک نشان داد، افزایش تحریم‌ها در ابتدای دهه 1390 و تشدید آنها طی سال‌های 1397 و 1398، موجب تشدید تاثیر نرخ ارز بر صادرات فولاد ایران به چین شده است. همچنین، طی دوره زمانی 1392 تا 1394 با طولانی شدن روند مذاکرات و تغییرات قیمت جهانی نفت همبستگی بین قیمت جهانی نفت و صادرات فولاد ایران به چین در بلندمدت تشدید شده است. نتایج گارچ چند متغیره نشان می-دهد که همبستگی بین نرخ ارز حقیقی و صادرات فولاد ایران به چین در بیشتر دوران منفی بوده است و همچنین همبستگی بین نرخ ارز حقیقی و قیمت نفت در بیشتر دوره مورد بررسی مثبت بوده است. بنابراینمی توان گفت فولاد از جمله کالاهای صادراتی ایران است که با افزایش قیمت نفت و افزایش درآمدهای نفتی موجب افزایش درآمدهای صادرات غیر نفتی ایران می‌شود.}, keywords_fa = {صادرات,فولاد,ایران,موجک,گارچ چند متغیره}, url = {https://journal.issiran.com/article_247779.html}, eprint = {https://journal.issiran.com/article_247779_88fd1a6a1705c83068d05b3d890b59f4.pdf} } @article { author = {Balali, Mostafa and Beynaghi, Mohsen and Khosravi, Mohammad}, title = {Investigation of simple shear extrusion steel mold and mechanical properties of nanostructured extruded samples of Al6061}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {106-112}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.540568.1211}, abstract = {The extrusion is used to produce samples with irregular cross-sections. In this process, the material is pressed along a straight extrusion channel using a special design. Simple shear extrusion steel mold was designed by Catia software. AISI 4140 and AISI D3 steel were used to make this mold and mandrel, respectively. The material of the mold and mandrel was selected based on the mechanical properties of steels and their application in industry. It is a new Sever Plastic Deformation (SPD) process to produce nanostructured material which is used to produce high strength material. The specimen dimensions remain unchanged. Results revealed that Simple Shear Extrusion (SSE) is superior compared to equal channel angular pressing (ECAP) in term of scrap material. They also concluded that strain and pressure distribution is more symmetric in specimen cross-section, in this method, which is an important advantage of SSE compared to other SPD processes. In this study, first, a SSE mold with specified form and dimensions, was fabricated. The cross-section of samples was square and the material was Al6061. After processing, the microstructure and mechanical properties of specimens, which were processed using different pass numbers, were investigated using tensile and impact tests, hardness evaluation, metallography. The results presented an improvement in the mechanical properties and microstructure. Due to finer grains, ductility of specimens was also improved in addition to an improvement in strength.}, keywords = {AISI 4140 steel mold,AISI D3 steel mandrel,sever plastic deformation,simple shear extrusion process,Microstructure,mechanical property}, title_fa = {بررسی قالب فولاد اکستروژن برشی ساده و خواص مکانیکی نمونه های اکسترود شده نانوساختار Al6061}, abstract_fa = {از اکستروژن برای تولید نمونه هایی با سطح مقطع نامنظم استفاده می شود. در این فرآیند، مواد در امتداد یک کانال اکستروژن مستقیم با استفاده از یک طرح خاص فشرده می‌شوند. قالب فولادی اکستروژن برشی ساده توسط نرم افزار Catia طراحی شده است. برای ساخت این قالب و سنبه به ترتیب از فولاد AISI 4140 و AISI D3استفاده شده است. مواد قالب و سنبه بر اساس خواص مکانیکی فولادها و کاربرد آنها در صنعت انتخاب شد. این یک فرآیند جدید Sever Plastic Deformation (SPD) برای تولید مواد نانوساختار است که برای تولید مواد با استحکام بالا استفاده می شود. ابعاد نمونه بدون تغییر باقی می ماند. نتایج نشان داد که اکستروژن برشی ساده (SSE) در مقایسه با پرس زاویه ای کانال مساوی (ECAP) از نظر مواد ضایعات برتر است. آنها همچنین به این نتیجه رسیدند که در این روش توزیع کرنش و فشار در مقطع نمونه متقارن‌تر است که مزیت مهم SSE در مقایسه با سایر فرآیندهای SPD است. در این تحقیق ابتدا یک قالب SSE با فرم و ابعاد مشخص ساخته شد. سطح مقطع نمونه ها مربع و جنس آن Al6061 بود. پس از پردازش، ریزساختار و خواص مکانیکی نمونه‌ها که با استفاده از اعداد عبور مختلف پردازش شده‌اند، با استفاده از آزمون‌های کششی و ضربه‌ای، ارزیابی سختی، متالوگرافی مورد بررسی قرار گرفت. نتایج بهبود در خواص مکانیکی و ریزساختار را نشان داد. با توجه به دانه های ریزتر، شکل پذیری نمونه ها نیز علاوه بر بهبود استحکام بهبود یافت.}, keywords_fa = {قالب فولادی AISI 4140,سنبه فولادی AISI D3,سخت تغییر شکل پلاستیک,فرآیند اکستروژن برشی ساده,ریزساختار,خاصیت مکانیکی}, url = {https://journal.issiran.com/article_248312.html}, eprint = {https://journal.issiran.com/article_248312_cbe807083163e950fafe473aede54948.pdf} } @article { author = {Khosravi, Mohammad and Azargoman, Majid and Torshizi, Hojjat}, title = {Modeling of weld bead geometry and optimization of GMAW welding parameters on CK45 steel}, journal = {International Journal of Iron & Steel Society of Iran}, volume = {18}, number = {1}, pages = {113-123}, year = {2021}, publisher = {Iron & Steel Society of Iran}, issn = {2981-0388}, eissn = {2981-0396}, doi = {10.22034/ijissi.2021.542242.1214}, abstract = {In the process of Gas Metal Arc Welding, achieving a favorable geometry meeting all requirements of the manufacturer is considered important. Therefore, for addressing these issues automated systems and modeling and optimization of the process are necessary. In the present study, empirical studies were carried out on CK45 steel considering four parameters including voltage, wire feed speed, welding speed, and welding nozzle angle as parameters affecting the welding geometry. Weld height and width were considered as the output parameter. Furthermore, for modeling the process, the surface response method was us, and finally, the process parameters were optimized using the particle pool method. The results obtained from the modeling have declared the voltage parameters of 17 wire feeding speeds of 244 welding speed of 160 and nozzle angle of 105 degrees as optimal. Examining the data predicted by the model and compared with the available experimental data, it is shown that by increasing both the wire speed and voltage and also minimizing the table speed, the width of the weld bead increases while increasing the voltage and wire speed and reducing the table speed, make the height of the bead to decrease. Hence, not only increasing the angle of the nozzle and wire-speed but also decreasing the voltage and table speed results in a decrease in the amount of dilution.}, keywords = {Bead Geometry,Gas Metal arc welding,RSM,Optimization,Dilution}, title_fa = {مدل سازی هندسه بستر جوش و بهینه سازی پارامترهای جوش GMAW بر روی فولاد CK45}, abstract_fa = {در فرآیند جوشکاری قوس فلزی گاز، دستیابی به هندسه مطلوب که تمام الزامات سازنده را برآورده می کند، مهم تلقی می شود. بنابراین برای رفع این مسائل سیستم‌های خودکار و مدل‌سازی و بهینه‌سازی فرآیند ضروری است. در مطالعه حاضر، مطالعات تجربی بر روی فولاد CK45 با در نظر گرفتن چهار پارامتر شامل ولتاژ، سرعت تغذیه سیم، سرعت جوش و زاویه نازل جوش به عنوان پارامترهای موثر بر هندسه جوش انجام شد. ارتفاع و عرض جوش به عنوان پارامتر خروجی در نظر گرفته شد. همچنین برای مدل‌سازی فرآیند، روش پاسخ سطحی ما بود و در نهایت پارامترهای فرآیند با استفاده از روش مخزن ذرات بهینه شدند. نتایج به‌دست‌آمده از مدل‌سازی، پارامترهای ولتاژ 17 سرعت تغذیه سیم 244 سرعت جوش 160 و زاویه نازل 105 درجه را بهینه اعلام کرده است. بررسی داده‌های پیش‌بینی‌شده توسط مدل و مقایسه با داده‌های تجربی موجود، نشان می‌دهد که با افزایش سرعت و ولتاژ سیم و همچنین به حداقل رساندن سرعت میز، عرض بسترجوش افزایش می‌یابد در حالی که ولتاژ و سرعت سیم افزایش می‌یابد و کاهش می‌یابد. با سرعت جدول، ارتفاع بستررا کاهش دهید. از این رو، نه تنها افزایش زاویه نازل و سرعت سیم، بلکه کاهش ولتاژ و سرعت میز باعث کاهش میزان رقت می شود.}, keywords_fa = {هندسه بستر,جوشکاری قوس فلزی گازی,روش پاسخ سطح,بهینه سازی,رقت}, url = {https://journal.issiran.com/article_248317.html}, eprint = {https://journal.issiran.com/article_248317_3e5833dd684e8e7abbc4f50024c3886b.pdf} }