research centers


Search results: Found 6

Listing 1 - 6 of 6
Sort by

Article
Parametric Optimization of Pulsed Nd:YAG Laser Lap Welding of Stainless Steel ASTM A240/ 316L with Carbon Steel ASTM A570/Gr30

Author: Thaier A. Tawfiq
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2017 Volume: 20 Issue: 1 Pages: 27-35
Publisher: Al-Nahrain University جامعة النهرين

Loading...
Loading...
Abstract

This work describes seam welding process using dissimilar ferrous metals by pulsed Nd:YAG. The main objective of this work is to achieve the best welding conditions. This imposes careful selection for the welding parameters and inevitably the well design of experiment (DOE). Sheets of ASTM A240/316L stainless steel to ASTM A570/Gr30 carbon steel all of 0.5 mm in thickness were lap welded. Different pulse energies or the related peak power, pulse duration, pulse repetition rate, and welding speeds were used. Moreover, different welding speeds were controlled by the employed manipulator. The laser beam spot diameter and the standoff distance were fixed. Experimental results are supported by the computational 2D and 3D models. In this article response surface methodology (RSM) was applied to design the experiment and obtain the best parameters through a set of mathematical models that define the weld characteristics. The results show that the best joint in term of joint strength is obtained at 31.9 J pulse energy (related to 5.5 kW peak power and 5.8 ms pulse duration), power density of 1.43×106 W/cm2, 1.5 Hz pulse repetition rate, and 0.5 mm/s welding speed.


Article
Corrosion Protection of Carbon Steel by Zn/PPY mCoating as Layers in 3.5% NaCl

Authors: S.I. Salih --- A.H. Ataiwi --- G.A. Mahdi
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 8 Part (A) Engineering Pages: 821-830
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

Plate from low carbon steel was took from oil pipelines, and coated with two layers, the first layer was done by sherardizing process at 400oC for variable periods (15, 30, 60, 120, 240)min, the second layer was applied by polypyrrole (PPY). The results showed that the thickness of sherardizing layer paint is increased when increasing treatment time (15, 30, 60, 120, 240 min). The corrosion performance was evaluated by using polarization method. In addition, it was examined morphological surface of paint layers by using scanning electron microscope (SEM). The results showed that the presence of polypyrrole layer with sherardized coatings, showned significantly increase in corrosion resistance, and coating of low carbon steel by using polypyrrole the conductive polymer with sherardizing process, drastically reduced from the corrosion current density values, as well as the corrosion rate of low carbon steel. The corrosion rate of the the polymer conductive coatings (PPY) on low carbon steel without sherardizing coating (as received) is 19.5 mpy while incorporation of PPY and sherardizing gives corrosion rate of 0.00371 mpy.


Article
Investigation Nano coating for Corrosion Protection of Petroleum Pipeline Steel Type A106 Grade B; Theoretical and Practical Study in Iraqi Petroleum Sector

Authors: M. J. Kadhim --- K. A. Sukkar --- A. S. Abbas --- N. H. Obaeed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 10 Part (A) Engineering Pages: 1042-1051
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

In the present investigation, titania (TiO2) nano-thin films were deposited on steel type A106-B, by using the Pulse Laser Deposition (PLD) technique to obtain passive layers of nano-coating. Electrochemical methods (Tafel completion) are used for study corrosion behavior of steel coating. The A106-B specimens were evaluated in 3.5 wt. % NaCl aqueous solution by using polarization technique with pH adjustment to 4.0 in order to determine the corrosion rate. The samples of TiO2 thin films were characterized by SEM, AFM, XRD, and FTIR. The input parameters were substrate temperature (100, 200 and 300) ’0C’, number of pulse (300, 400 and 500) and fluencies energy (800, 900 and 1000) mJ/cm2, have been investigated to detect their impact on corrosion reduction rate using Taguchi methodology orthogonal array and Analysis of Variance (ANOVA).The ANOVA results indicates that number of shoots pulse significantly affecting the corrosion rate in PLD technique, which is highest among the contributions of the other parameters which is (58.03%) about three times of the fluencies energy (19.12%).The results show that the TiO2 deposition on steels offers an excellent corrosion resistance about 99 times as compared with uncoated steel. The optimum conditions to minimum values corrosion rate are: temperature of 300ºC, number of laser pulses at 300, and fluencies energy equal to 1000 mJ/cm2. Finally the optimal parameters that was used to predict the conclusions were (98.6) to the response of corrosion rate.


Article
Study the Change of Current Weld on Mechanical Properties and Microstructure of Low Carbon Steel Welded by Electric Arc Welding

Author: Wafa Mahdi Jodia
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2017 Volume: 25 Issue: 4 Pages: 1470-1477
Publisher: Babylon University جامعة بابل

Loading...
Loading...
Abstract

The welding is one of necessary and important process which is used in manufacturing operations to join two or more materials of the similar or dissimilar pieces to achieve complete cohesion. This work focuses on the effect of current change and welding method during welded low carbon steel (steel 37) by electric arc welding on microstructure and mechanical properties such as (tensile strength, hardness and impact strength ). The welding currents were chosen are (60, 80, 100, 120, 140 and 160A ), and the weld was done by two directions ( top and bottom sides). The tensile, impact, hardness and microstructure tests were done to locate the mechanical properties of the welded joint. The results showed that when the welding current increase, the tensile strength was increase from (349.07 to 369.44)MPa while the impact strength and hardness decrease. Microstructure of welding region has been dealt with it for each sample and for every increase of welding current

اللحام هو واحد من العمليات الضرورية و التي تستخدم في عمليات التصنيع لربط قطعتين او اكثر من مواد متشابه او غير متشابه لتحقيق التماسك الكامل. في هذا العمل تم التركيز على تأثير تغير التيار وطريقة اللحام خلال لحام الفولاذ الواطئ الكاربون (فولاذ37) بلحام القوس الكهربائي على البنية المجهرية و الخواص الميكانيكية مثل (مقاومة الشد، الصلادة و مقاومة الصدمة). وقد تم اختيار تيارات اللحام (60، 80، 100، 120، 140، 160 أمبير) و تم اللحام باتجاهين (من الاتجاهين الاعلى والاسفل). وقد اجريت اختبارات الشد، الصدمة، الصلادة والبنية المجهرية لتحديد الخواص الميكانيكية لربطة اللحام. اظهرت النتائج انه عند زيادة تيار اللحام، مقاومة الشد تزداد من (349.07 الى 369.44) ميكا باسكال بينما مقاومة الصدمة والصلادة تقل. البنية المجهرية لمنطقة اللحام سجلت لكل عينة ولكل زيادة لتيار اللحام.


Article
Bending Characteristics of Carburized Low Carbon Steel Experimental and Numerically Study

Author: Mohamad K. Alwan Alsaadi
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2017 Volume: 25 Issue: 2 Pages: 761-773
Publisher: Babylon University جامعة بابل

Loading...
Loading...
Abstract

This research includes experimental and numerical studies by using finite element method to study the effect of carburized low carbon steel for different beams width on the hardiness and bending properties.The back of carburization consists from hardwood charcoal mixed with barium carbonate as the Activator. The specimens were carburized using (30%) of Activator at temperature equal to (900ºC) for five hours.The modulus of elasticity obtained from experimental work used in FEM (ANSYS) to calculate flexural strength, maximum strain and maximum shear stress and these results increase with carburized low carbon steel. The results of the study showed that the Vickers micro hardness increased, the maximum flexural strength (1750 MPa) and maximum shear stress was (121.5 MPa) at width (16 mm) for the experimental results carburized low carbon steel. The experimental, finite element and analytical results obtained for the bending analysis are approximately agreement.

تضمنت الدراسة الجانب العملي و تقنية العناصر المحددة لمعرفة تاثير كربنة الفولاذ المنخفض الكربون على قيم الصلادة وخواص الانحناء لعرض اعمدة مختلف.أن وسط الكربنة مكون من مسحوق الفحم النباتي مع كاربونات الباريوم كمادة منشطة.وأن العينات يتم كربنتها بأستخدام نسبة (30%) من مادة التنشيط وعند درجة حرارة (900ºC) ولمدة خمسة ساعات .النتائج العملية لمعامل المرونة استخدمت في تقنية العناصر المحددة (برنامج انسيز) لحساب مقاومة الانحناء واكبر انفعال واكبر اجهاد قص بينت النتائج زيادة هذه القيم بعد كربنة الفولاذ منخفض الكربون.كذلك بينت النتائج أن الصلادة المجهرية للسطح المكربن تزداد, متانة الانحناء (1750 MPa) واكبر اجهاد قص (121.5 MPa) عند عرض عمود(16 mm) بعد الكربنة للنتائج العملية .و كذلك كانت نتائج العناصر المحددة مقاربة للنتائج العملية.


Article
Studing effect of static concentration for chemical machining on surface roughness and metal removal rate for low carbon steel
دراسة تأثير تركيز المحلول الساكن في عملية التشغيل الكيميائي على الخشونة السطحية ومعدل الازالة المعدنية للفولاذ منخفض الكاربون

Author: نسرين داخل فهد
Journal: Muthanna Journal of Engineering and Technology(MJET) مجلة المثنى للهندسة والتكنولوجيا ISSN: 25720317 25720325 Year: 2017 Volume: 5 Issue: 1 Pages: 22-26
Publisher: Al-Muthanna University جامعة المثنى

Loading...
Loading...
Abstract

Chemical machining is one of non traditional machining methods. It is necessary to study the main foundations of the process and the parameters affecting this process. In this research worked to reach the higher surface smoothness and lowest metal removal when a low carbon steel alloy was machined. Been using this alloy of chemically machined using etchant solution (Ferric chloride FeCl3) .Factors that have been studied: machining time and concentration of etchant where three concentrations were studied (20, 40 and 60%). Each sample was machined by different times (1, 3, 5, 7 and 9 min).Metal removal rate was calculated depending on weight loss due to chemical machining based on corrosion mechanism. Performed tests hardness, surface roughness and an atomic force microscope examination of the surfaces of the samples chemically machined before the process and after it.Results showed that minimumsurface roughness recorded in chemical machining when concentration of etchant (60%) and time (1) min. Among the factors used in the study concentration of etchant was the most important influence on metal removal rate and surface roughness.

تعتبر عملية التشغيل الكيميائي من طرق التشغيل الغير تقليدية، ومن الضروري دراسة الاسس الرئيسية للعملية و العوامل المؤثرة على الطريقة. تم في هذا البحثالوصول الى اعلى نعومة سطحية و باقل معدل تأكل عند تشغيل احد سبائك الفولاذ منخفض الكاربون الواسعة الاستخدام. تم استخدام هذه السبيكة لتشغيلها كيميائيا باستخدام محلول المحفر(Ferric chloride FeCl3). العوامل المؤثرة التي تم دراستها: زمن التشغيل وتركيز المحفر حيث تمت دراسة ثلاث تراكيز للمحفر (20، 40 و 60%) كل عينة تم تشغيلهابازمان مختلفة (1، 3، 5، 7 و 9دقيقة). معدل الازالة المعدنية تم حسابه بالاعتماد على الفقدان بالوزن كونالية التشغيل الكيميائي تعتمد على التأكل. اجريت فحوصات الصلادة والخشونة السطحية والفحص بمجهر القوة الذرية لسطوح العينات المشغلة كيميائيا قبل عملية التشغيل الكيميائي وبعدها.اوضحت النتائج ان اقل خشونة سطحية سجلت في النموذج المشغل كيميائيا عند تركيز المظهر (60%) و زمن (1) دقيقة . وتبين من بين العوامل المستخدمة في الدراسة تركيز المظهر كان التأثير الاهم على معدل الازالة المعدنية والخشونة السطحية للسطح المشغل.

Listing 1 - 6 of 6
Sort by
Narrow your search

Resource type

article (6)


Language

English (5)

Arabic (1)


Year
From To Submit

2017 (6)