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Article
Study of Fatigue Fractography of Mild Steel Used in Automotive Industry
دراسة مقطع كسر الكلال للفولاذ المطاوع المستخدم في صناعة السيارات

Author: Ahmed Ameed Zainulabdeen احمد عميد زين العابدين
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2019 Volume: 15 Issue: 1 Pages: 82-88
Publisher: Baghdad University جامعة بغداد

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Abstract

Fatigue failure is almost considered as the predominant problem affecting automotive parts under dynamic loading condition. Thus, more understanding of crack behavior during fatigue can strongly help in finding the proper mechanism to avoid the final fracture and extent the service life of components. The main goal of this paper is to study the fracture behavior of low carbon steel which is used mostly in automotive industry. For this purpose, the fractography of samples subjected to high and low stress levels in fatigue test then was evaluated and analyzed. Hardness and tensile tests were carried out to determine the properties of used steel. Also, the samples were characterized by microstructure test and XRD analysis to examine the constitute phases. The fatigue test (S-N curve) was done at stress ratio (R= -1), and the fracture examination was perform using Scanning Electron Microscope (SEM). The results of microstructure and XRD analysis were indicating that the Ferrite and a little amount of pearlite are the dominant phases of this steel. Whereas, the fractography observations reveal that the void coalescence ductile fracture is the main failure mode in samples with high stress level, while the ductile fracture (void coalescence) with Transgranular Cleavage fracture was noticed in low stress fatigue mode for this alloy.

يعد فشل الكلال من أخطر المشاكلات الشائعة المؤثرة على أجزاء السيارات المعرضة لأحمال دورانية. لهذا فان فهم سلوك الشقوق اثناء حدوث الكلال يساعد على تجنب حدوث الفشل النهائي للجزء اثناء الخدمة واطالة عمره. ان الهدف الأساس للبحث هو دراسة سلوك الكسر للفولاذ الواطئ الكربون والمستخدم في صناعة السيارات. لهذا السبب، تم دراسة مقطع الكسر للكلال عند احمال كلال واطئة وعالية لتقويم الأجزاء وتحليلها. كما تم اجراء اختبارات الصلادة والشد لتحديد خواص الفولاذ المستخدم. كذلك، تم توصيف المادة عن طريق دراسة البنية المجهرية ودراسة حيود الاشعة السينية لتفحص الاطوار والمكونات للسبيكة. ان اختبار الكلال (الاجهاد-عدد الدورات) تم اجراءه عند نسبة اجهاد (R=-1)، وتم دراسة مقطع الكسر باستخدام المجهر الالكتروني الماسح (SEM). اشارت نتائج الفحص المجهرية والاشعة السينية بان الطور السائد لهذا النوع من الفولاذ هو الفرايت مع نسبة قليلة من البيرلايت، بينما اظهر مقطع الكسر تكون كسر مطيلي بالتحام الفجوات حيث ان هذا هو الأسلوب عند اجهادات عالية، بينما أظهرت النتائج عند اجهادات كلال واطئة تكون الكسر الانقسامي تكون الكسر المطيلي الناتج عن التحام الفجوات لهذه السبيكة.

Keywords

Automotive --- fatigue --- fracture --- mild steel.


Article
Corrosion Inhibition of Galvanic Couple Copper Alloy/Mild Steel in Cooling Water System

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Abstract

The driving idea for the present work was to combine the effect of polyvinyl alcohol (PVA) as corrosion inhibitor with the distance between the anodic and cathodic elements of the galvanic cell, beside their area ratio, in scope of synergistic suppression of galvanic corrosion on Cu/Fe model couple, using weight loss method. The performance affecting galvanic corrosion process has been tested for three major factors affect the process:1.Four PVA inhibitor concentrations were selected to be (0, 1000, 4000 and 7000 ppm) in simulated cooling water.2.Two cathode: anode area ratios as 1:1 and 2.4:1.3.Two distances apart cathode – anode as 3 and 7 cm. Maximum corrosion inhibition achieved was 86% which indicates that increasing inhibitor concentration leads to decrease dissolution process followed hydrogen evaluation Cu electrode as cathode element in galvanic cell.


Article
Study of Some [N-substituted] p-aminoazobenzene as Corrosion Inhibitors for Mild-Steel in 1M H2SO4

Authors: Hanan H. Al-Doori --- Mehdi S. Shihab
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2014 Volume: 17 Issue: 3 Pages: 59-68
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Azo dye derivatives were prepared as corrosion inhibitors for mild steel in 1M H2SO4 solution by weighting loss measurements as evaluation tools. It has been observed that inhibition efficiency orders are A1> A3> A2with the highest inhibiting efficiency of 82% for 10−3M. Increasing in inhibitor concentration accompanies with corrosion rate decreases, inhibition efficiencies increase and surface coverage degree increases. Semi-empirical molecular orbital calculations of prepared compounds A1, A2, and A3 as molecular models gave useful information to predict the interaction between the surface of metal and the organic molecules as corrosion inhibitors.

تم تحضير المركبات الازو دايزالتي تم الرمز اليها بالرموز (A1, A2, A3) كمثبطات لتأكل معدن الحديد المعامل في الحامض الكبريتيك بتركيز 1 مولاري بواسطة قياسات الفقدان بالوزن حيث تم ملاحظه كفاءه التثبيط لهذه المركبات كالاتي :A1>A3>A2 علما ان التاكل على سطح المعدن تقل بزيادة كفاءة المثبط وذلك لان نسبه التغطية (A1, A2, A3)على سطح المعدن تزداد بزيادة تركيز مثبط التاكل. الحسابات الجزيئيه للمركبات (A1, A2, A3) اعطت معلومـات مفيـدة لتوضيح التأثـر بين السطـح المعـدن والجزيئات العضوية كمثبط للتأكل.


Article
Preparation and Study of Some Pyridinium Chloride Derivatives as Corrosion Inhibitors for Mild-Steel in 1M H2SO4 Aqueous Solution

Authors: Atheer Fadhel Mahmood --- Mehdi Salih Shihab
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2015 Volume: 18 Issue: 3 Pages: 16-23
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Pyridinium chloride derivatives, namely: 1-benzyl-4-(2-cyclohexylidenehydrazinecarbonyl) pyridinium chloride, C1; 1-benzyl-4-(2-(1-phenylethylidene) hydrazinecarbonyl) pyridinium chloride, C2; 1-benzyl-4-(2-(diphenylmethylene)hydrazinecarbonyl) pyridinium chloride, C3, were prepared and studied as corrosion inhibitors for mild steel in 1M H2SO4 aqueous solution using weighting loss measurements for 24 hours at 30oC. The results showed that inhibition efficiency for all pyridinium chloride derivatives have rapprochement in value with the highest concentration. Increasing in inhibitor concentration accompanies with corrosion rate decreases, inhibition efficiencies increase and surface coverage degree increases. The free energy values of adsorption revealed physisorption effect for (C1, C2, and C3) and gave useful information to predict the interaction between the surface of metal and the organic molecules as corrosion inhibitors.

تم تحضير وتشخيص مشتقات كلوريد البيريدينيوم، وهم (C1) 1- بنزيل 4- (سايكلو هكسايل داين هيدرازين كاربونيل ) كلوريد البيريدينيوم, (C2), 1-بنزيل 4- (2- فينل أثلين داين) كلوريد البيريدينيوم و (C3) 1-البنزيل-4- (2-(ثنائي فنيل مثلين) هيدرازين كاربونيل) كلوريد البيريدينيوم، وتمت دراسة هذه المركبات العضوية كمثبطات لتآكل الحديد الصلب في محلول مائي لحامض الكبريتيك بتركيز 1 مولاري ولمدة 24 ساعة في درجة حرارة 30 درجة مئوية. وباستخدام قياسات فقدان الوزن, حيث أظهرت النتائج أن كفاءة التثبيط لجميع مشتقات كلوريد البيريدينيوم تتناسب طرديا مع تركيز المثبط في المحلول. وجد بأن زيادة تركيز المثبط يؤدي الى انخفاض معدل التآكل، وارتفاع كفاءة التثبيط تعني زيادة في تغطية سطح المعدن. كما تم حساب قيم طاقة كبس الحرة للامتزاز وتبين ان نوع الامتزاز هو فيزياوي على سطح المعدن للمركبات (C3 , C2 , C1) وقد تم الحصول على معلومات مفيدة للتنبؤ بالتفاعل الحاصل بين جزيئات المركبات العضوية كمثبطات لتأكل سطح المعدن.


Article
Green Corrosion Inhibitor for Protection of Mild Steel

Author: S.A. Ajeel
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 9 Part (A) Engineering Pages: 914-921
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In the present work, corrosion inhibition of Mild steel in 1M H2SO4 solution by Rosmarinus Officinalis Leaves extract was studied by weight loss and potentiostatic methods. Increasing acid concentration leads to an increase in the corrosion rate of the electrode. The variable conditions used in this investigation are (100 to 1000 ppm at 25oC. Rosmarinus Officinalis Leaves extract for Mild steel. It has been found that the concentrates as a compelling consumption inhibitor for gentle steel in acidic medium. The hindrance process is credited to the development of an adsorbed film of inhibitor on the metal surface, which secures the metal against corrosion. The inhibition efficiency was observed that increase with increasing inhibitor concentration up to maximum 92% for 1000 ppm at 25 oC. The results show that the corrosion rate without inhibitor is 5.6 mpy while with inhibitor be 0.43 mpy, that is mean the corrosion rate was improved more than 90%. The effects of immersion time (2 h) at 25oC on the inhibition of corrosion have also been improved corrosion resistance. The results obtained show that Rosmarinus Officinalis Leaves Extract could serve as an excellent friendly green corrosion inhibitor. FTIR results indicate that this herb containing different chemical bonds (C-C, CH2, C-O-C, Cellulose) with steel surface producing barrier layer to protect the surface


Article
The Effect of Tool Geometry for Resistance Spot Welds on Crack Growthin Specimens of Mild Steel
تأثیر شكل العدة لعملیة اللحام النقطي المقاوم على نمو الشق لوصلة من الفولاذ

Author: Nadhim M.Faleh
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2013 Volume: 31 Issue: 12 Part (A) Engineering Pages: 2242-2250
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

A mechanism of crack growth was investigated in resistance spot welds of mildsteel. The experiments in this study were designed to investigate the effects of theelectrode cap geometrieson fatigue life of the resistance spot weld specimens. Twotypes of electrode cap geometries were used. These types are 4.8 mm and 6.3 mmnose,used with the same shank in welding operations of 2mm mild steel plate. Toobtain the goal, operating factors were precisely controlled, especially the electrodeforce and welding current of spot welds, to keep the same operating conditions whilechangingthe electrode geometries. The life test results showed an improvement in thefatigue life of resistance spot welds. The increment was 30% in heavy loads and 10%in low loads based on tool geometry. The improvement in the fatigue life wasproduced by reducing the diameter of the nose in the geometry of the tool.


Article
Corrosions inhibitions of milds steelsin hydrochloricsacid solutionsby an isatinaniline compound

Author: Khalida.F. Al-Azawi
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 2 Part (B) Engineering Pages: 98-103
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Recently the researchers go to the eco-friendly corrosion inhibitors.In the present investigation, isatin which found in many plants, Isatis tinctoria,Calanthe discolor and Couroupita guianensis has been used as corrosioninhibitor. An isatin-aniline compound, namely ethyl 4-amino-N-(3-isatinyl)benzoate (AIB), was successfully synthesized in high yield and its inhibitionimpact on corrosion of MS (mild steel) in hydrochloric acid as corrosivesolution was examined via weight loss and Scanning electron microscopetechniques. The results acquired appeared that AIB has employ perfect as acorrosion inhibitor at low concentrations towards mild steel in HCl bath. Theimpact of temperature on the corrosion behavior of MS in corrosive bath withpresence of (250) ppm of AIB has been investigated in the range oftemperatures (303-333) K. The thermodynamic parameters for inhibitingprocess were investigated to find out the mechanism of corrosion inhibition ofMS acid bath.


Article
USING OLIVE STONE POWDER FOR STEEL CORROSION INHIBITION

Authors: Rami Adel Qassim --- Sahib Mohammed Mahdi --- Jafar Ghani Majeed
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2018 Volume: 22 Issue: 2 (Part-1) Pages: 1-9
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

corrosion of metals is the most significant and difficult life problems, especially its produce an economical losses, therefore, many researches carried out in various fields in order to reduce the bad effect of corrosion, particularly in acidic environments. Using corrosion inhibitors is one of the methods of prevention corrosion, which come up on organic and inorganic materials, in this study, dried Olive stone powder used as corrosion inhibitor in solutions of hydrochloric acid with concentrations of 0.5, 1 and 1.5 molarity at room temperature, where 10 gm per litter of acid. The corrosion rates of mild steel samples were measured using potentiostat device with reference of calomel electrode. The result shows that corrosion rate reduced by adding the Olive stone powder. The highest inhibition efficiency percent for acid solutions with concentration of 1.5 molarity is 82.9%, while the lowest was 64.1% in the 0.5 molarity solution, and in the 1 molarity solution was 77.6%. The chemical composition of the Olive stone powder is shown to be an organic matter of a high carbon and hydrogen content making a carbonyl compound which has the greatest effect in inhibition corrosion in acidic solutions such as hydrochloric acid.


Article
Effect of laser process an inclined surface cutting of mild steel then analysis data statistically by RSM
تحليل البيانات احصائيا لنهج خشونة السطح المثلى عن طريق القطع بالليزر للفولاذ الطري

Author: Kamil Jawad Kadhim كامل جواد كاظم
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2019 Volume: 25 Issue: 10 Pages: 120-133
Publisher: Baghdad University جامعة بغداد

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Abstract

The regression analysis process is used to study and predicate the surface response by using the design of experiment (DOE) as well as roughness calculation through developing a mathematical model. In this study; response surface methodology and the particular solution technique are used. Design of experiment used a series of the structured statistical analytic approach to investigate the relationship between some parameters and their responses. Surface roughness is one of the important parameters which play an important role. Also, its found that the cutting speed can result in small effects on surface roughness. This work is focusing on all considerations to make interaction between the parameters (position of influence) because laser power directly depends on cutting speed with high gas pressure and vice versa to obtain a less surface roughness. Data analysis showed that the lower value for roughness was (0.68) µm and the high roughness was (8.56) µm. The model values for considered fit are suggested to be as (R2) = 51.76%. The selected coefficient is referred to the amount of model variation in the response. The adjusted value of (R2) = 8.34% will calculate the number of forecasting model and is normally useful for comparing models with different numbers of predictions. The (F) test is used to determine whether interaction and major effects are significant. The p-value is the probability of obtaining a statistic test which is considered as the extreme of actual calculated values if the null hypothesis is true. A commonly cut-off value that used for the p-value is (0.05). This value is used to be the active contribution to investigate the correlation between laser machining parameter with the surface roughness. Also the goal of this research highlights the experimental control parameters of mild steel laser processing with their responses.

باستخدام منهجية التصميم التجربية (DOE) تم تطوير نموذج رياضي بشكل أساسي من خلال تحليل الانحدار لدراسة التنبؤ بالاستجابة . ثم تم تصميم التجربة باستخدام طريقة متسلسلة من المنهج التحليلي الاحصائي المنظم لدراسة العلاقة بين المدخلات والمخرجات .علما ان تقنية الحل الخاصة المستخدمة في هذة الدراسة هي منهجية سطح الاستجابة(RSM) وكانت نتائج خشونة السطح متباينة ولذلك لعبت دورا هاما , لابد من ايجاد الحلول المناسبة لها . وتبين ان سرعة القطع يمكن ان تؤدي الى خشونة اقل . في كل تطبيق تم التركيز على التفاعل بين العوامل ,عندما كانت قوة الليزر تعتمد مباشرة على سرعة القطع حيث ارتفاع ضغط الغاز , والعكس بالعكس للحصول على أقل خشونة للسطح . وجرى تحقيق الربط بين هذه العوامل وعملية القطع بالليزر مع خشونة السطح الناتج موضح بشكل تفصيلي في المخططات التحليلية . وكانت اقل خشونة تم الحصول عليها من قياس ثلاث مناطق من العينة بعد اخذ المعدل هي 0.68, 8.56 مايكرون على التوالي. وكذلك تبين R2 (R-sq) معامل التحديد يشير إلى مقدار التباين في الاستجابة الموضح بالنموذج. كلما زادت نسبة R2 ، كلما كان النموذج أفضل للبيانات الخاصة بالتجربة. Adjusted R2 (R-sq Adj) حسابات لعدد المتنبئين في النموذج الخاص بالتجربة ومفيد لمقارنة النماذج مع أعداد مختلفة من تنبؤات. P-valueإن القيمة ((p هي احتمال الحصول على إحصائية اختبار تكون متطرفة على الأقل كالقيمة المحسوبة الفعلية إذا كانت فرضية الخطأ صحيحة. قيمة القطع المستخدمة بشكل شائع لقيمة p هي 0.05 ، إذا كانت قيمة p المحسوبة لإحصائية اختبار أقل من 0.05 .F) ) اختبار لتحديد ما إذا كان التفاعل والآثار الرئيسية كبيرة. كما يسلط بحثنا الضوءعلى عوامل السيطرة التجريبية من الليزرالمثالي المصحح و معالجة الليزر مع المخرجات المثالية .


Article
Measurement of temperature distribution for "CO2 laser –mild steel processing" By non-Contact methods
قياس توزيع درجات الحرارة عن بعد لليزر ثاني اوكسيد الكاربون اثناء معالجة الفولاذ

Author: Jasim Hassan Rasheed
Journal: Diyala Journal For Pure Science مجلة ديالى للعلوم الصرفة ISSN: 83732222 25189255 Year: 2012 Volume: 8 Issue: 2 Pages: 68-82
Publisher: Diyala University جامعة ديالى

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Abstract

Measurement of temperature distribution by non- contact method ( Digital camera Cyclops52) are achieved . Outline to non-contact techniques is given Fundamental and basic terms ofradiation laws are mentioned. Carbon dioxide laser Everlaser 525 (500w)is employed as aheat source to process mild steel under investigation at different pressures and powers .

واعطیت . (Cyclops تم انجاز ھدف البحث وھو قیاس توزیع درجة الحرارة عن بعد بواسطة الكامیرا الرقمیة ( 52خلاصة عامة لتقنیات القیاس عن بعد كما تمت الإشارة الى القوانین الاساسیة للاشعاع .واستخدم لیزر ثاني اوكسید الكاربون ( 500 واط ) كمصدر حراري اثناء معالجة الفولاذ تحت ضغوط وقدرات مختلفة .

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