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Article
Study of Annealing, Hardening and Tempering on Hardness
دراسة تأثير التلدين ، التصليد والمراجعة على الصلادة والبنية المجهرية

Author: Nuha. H. AL- Hasan نهى هادي الحسن
Journal: Journal of Basrah Researches (Sciences) مجلة ابحاث البصرة ( العلميات) ISSN: 18172695 Year: 2010 Volume: 36 Issue: 3A Pages: 22-28
Publisher: Basrah University جامعة البصرة

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Abstract

In this study, the effects of heat treatments annealing ,hardening and tempering on the microstructure and hardness of Mn-Fe Alloy were investigated. The Mn-Fe alloy samples were annealed at 900◦C for 20 min then cooling inside furnace and hardened treatment at 900◦C for 20 min with cooling by water, oil, and salts solution. The specimens were subsequently tempered at temperatures of 100 oC, 290 oC, 350 oC and 500oC. The microstructures, and hardness properties of these samples were analyzed and compared with samples without treatment. The microscopic examinations showed that difference in grains size for samples before and after heat treatments. The result showed that tempering of Mn-Fe Alloy samples (0.3%C) significantly exhibited better hardness as compared with that of Mn-Fe alloy without treatments .

في هذه الدراسة ، تم التعرف على تأثير المعاملات الحرارية :التلدين، التصليد والمراجعة على البنية المجهرية وخاصية الصلادة في سبيكةMn – Fe . عينات سبيكة Mn – Fe لدنت بدرجة حرارة 900◦C لمدة 20 min وبردت داخل الفرن وعوملت بالتصليد بدرجة حرارة 900◦C لمدة 20 min وبردت في الماء والزيت ومحلول ملحي. بعدها تم مراجعة العينات في درجات الحرارة من 100 oC 290oC, 350 oC, و 500oC .تم تحليل البنى المجهرية وخاصية الصلادة لهذه السبيكة ومقارنتها مع عينة من دون معاملة ، تم فحص البنى المجهرية للعينات قبل المعاملة الحرارية وبعد تغيرها . واظهرت النتائج ان معاملة سبيكةMn – Fe (0.3%C) يؤدي الى الحصول على أفضل الخصائص الميكانيكية بما في ذلك ارتفاع الصلادة بالمقارنة مع سبيكة Mn – Fe بدون معاملة.


Article
Mechanical Properties of Tempered Nanobainite Steel
الخواص الميكانيكية لصلب النانو بايانايت والمراجع حرارياّ

Authors: Dhafir S. Al-Fattal --- Najmuldeen Y. Mahmood
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2013 Volume: 31 Issue: 1 Part (A) Engineering Pages: 107-119
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The mechanical properties of 62 SiMnCr 4 steel transformed isothermally at 280ºC for 5-hours were investigated. The hardness of nanobainite steel was equivalent to tempered martensite steel. The hardness decreases significantly at high tempering temperatures in excess of 500ºC. Yield strength of about 2GPa and ultimate tensile strength of 2.3GPa have been achieved for nanobainite steel. Furthermore, the high strength is frequently accompanied by relatively good percentage elongation of 8.25%. The strength decreases and the ductility increases with increasing tempering temperature. Nanobainite steel has a high charpy impact energy of 170 J which decreases linearly with increasing tempering temperature. Fatigue strength of nanobainite steel is higher than tempered martensite, its decreases with increasing tempering temperature.

تم دراسة الخواص الميكانيكية للصلب62 SiMnCr 4 المتحول بدرجة حرارية ثابتة هي 280ºCولمدة خمس ساعات الى طور البايانايت الدقيق جداّ (Nanobainite). ان صلادة البايانايت كانت مكافئة لصلادة المارتنسايت المراجع (Tempered martensite). تتناقص صلادة البايانايت بشكل واضح اثناء المراجعة الحرارية في درجات الحرارة التي تتجاوز 500ºC. تم الحصول على مقاومة خضوع ومقاومة شد بحدود (2 GPa) و (2.3 GPa)على التوالي,وإضافة لهذه المقاومة العالية فقد تم الحصول على نسبة استطالة جيدة نسبياّ(8.25%). تتناقص المقاومة وتزداد المطيلية بزيادة درجة حرارة المراجعة. للبايانايت طاقة صدمة عالية بحدود (170 J) وتتناقص خطيا بزيادة درجة حرارة المراجعة. لصلب البايانايت مقاومة كلال اعلى من المارتنسايت المراجع وتتناقص مقاومة الكلال مع زيادة درجة حرارة المراجعة.


Article
A Method For Detect Forgery from Images
طريقة لكشف التزوير من الصور

Authors: Hanaa Mohsin Ahmed --- Sabaa Rakan Salim
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2015 Volume: 33 Issue: 2 Part (B) Scientific Pages: 259-272
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Due to the availability of many image editing and processing tools, it is possible to easily change the information represented by a digital paintings without leaving any obvious traces of tampering, which led to the problem of verification image. These issues of multimedia security have led to the development of several approaches to tampering detection. Digital image forensic is a branch that deals with the identity and authenticity of the images. The proposed system is the Verification system for paintings. Where the Verification system used non-blind passive image forensic, and that it has been achieved by using fuzzy gradient based image reconstruction, which is able to detect all types of forgery (Splicing, Image Retouching, Geometrical Transformation, Copy Move Attack, other type) and also able to compute forgery ratio as percentage.This methodology has its application in a context where the source image is available.The experimental results show that the algorithm can effectively locate the tampered area in multi block size 4X4 of any type, and using fuzzy process is obtained a good result to reduce time consuming for solving image reconstruction and also enhancement reconstruction image .

نظرا لتوفير العديد من برامج تحرير الصور وادوات معالجتها ,اصبح من الممكن التغير بسهوله على المعلومات التي تحملها اللوحات دون ترك اي اثار واضحه عليها جراء العبث بها والتي ادت الي مشكله التحقق من الصور. ومما ادت هذه القضايا امن الوسائط المتعدده في تطوير طرق الكشف عن التلاعب. الطب العدلي الالكتروني هو الفرع الذي يتعامل مع الهوية والأصالة في الصور والذي يهدف الى كشف العبث في الصور الرقميه .النظام المقترح هو نظام تحقيق للوحات الفنيه حيث يستخدم طريقة (non-blind passive image forensic) والتي تحققت باستخدام ، إعادة بناء الصورة على أساس التدرج غامض، التي تهدف الى كشف جميع انواع التزوير (التحويل الهندسي، اعادة لمس الصورة، الربط، هجوم نقل نسخة، وغيرها) وايضا القدرة على حساب نسبة التزوير كنسبة مئوية، واظهر النتائج التجريبية أن النظام المقترح يحقق دقة 100٪ للكشف عن جميع انواع التزوير، مع القدرة على تحسين الصورة.


Article
Optimization of Heat Treatment Parameters for the Tensile Properties of Medium Carbon Steel

Authors: Abbas Kh. Hussein --- Laith K. Abbas --- Wisam N. Hasan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 10 Part (A) Engineering Pages: 1091-1099
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determination optimal factors of heat treatment (tempering temperature, percentage of nanoparticles, type of base media, nanoparticles type and tempering time)for increasing ultimate tensile strength, yield strength and ductility properties of medium carbon steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion. The importance levels of process parameters on tensile properties were obtained by using analysis of variance, which applied with the help of (Minitab18) software. Percentage of volumetric fractions of nanoparticles with three different levels(0.01, 0.03 and 0.08 %) were prepared by dispersing nanoparticles that are (α-Al2O3,TiO2 and CuO) with base fluids (De-ionized water, salt solution and engine oil).Medium carbon steel specimens were suffered to hardening and tempering heat treatment process. The variables of tempering heat treatment were temperatures (400 C˚, 550 C˚) and a soaking times (30, 45 and 60 minutes) respectively. Tensile testing performed on samples using united universal hydraulic machine. The results for ( S/N) ratios showed the order of the factors in terms of the proportion of their effect on ultimate tensile strength, yield strength and ductility properties as follow: Tempering temperature ( 400 C˚) ,Nanoparticles type (TiO2 ),Tempering time (30 min),Type of base media (salt solution, engine oil) and Percentage of nanoparticles ( 0.03%) was the least influence for ultimate strength and yield strength while for the elongation were as follows: Tempering temperature (550 C˚),Tempering time(60min), Nanoparticles type (CuO),Type of base media (deionized water) and last percentage of nanoparticles (0.08%).


Article
Effects of Heat Treatment and Surface Finish on the Crevice Corrosion Resistance of Martensitic Stainless Steel

Authors: Fatima Sameer Ahmed فاطمة صبيح احمد --- Haider M. Mohammad حيدر معاذ محمد
Journal: Basrah Journal for Engineering Science مجلة البصرة للعلوم الهندسية ISSN: Print: 18146120; Online: 23118385 Year: 2017 Volume: 17 Issue: 2 Pages: 9-17
Publisher: Basrah University جامعة البصرة

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Abstract

The present study aims to investigate the influence ofheat treatment and surface finish on the behavior of crevicecorrosion resistance of AISI 410 and 416 martensitic stainlesssteels thus, to quantify the conditions at which crevicecorrosion minimize as possible. The experimental work carriedout during this study involves material selection, chemicalcomposition tests, specimens preparation before heattreatments, austenitizing at temperature range (925-1010˚C)and for holding time periods of (30, 45 and 90 min), air and oilquenching followed by tempering at heating range of (205-605 ̊C) and for 45 min, micro hardness tests, specimensgrinding, surface roughness measurements, crevice corrosiontests, crevice evaluation and microstructure tests.Theoretically, empirical equations for crevice maximum depthunder the effect of surface roughness and hardness for bothAISI 410 and 416 steels were determined. While formicrostructure analysis, carbides average area was determinedby using the ImageJ analysis program and a mathematicalmodel was also predicted. Results showed that like hardness andsurface roughness increase crevice corrosion resistancedecreases. Therefore, material treated by annealing canminimize crevice corrosion rates more than that treated withhardening.


Article
Effect of Tempering Temperature on Wear Rate of Steel 100Cr6
تاثير درجة حرارة المراجعة على معدل البلى لفولاذ 100Cr6

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Abstract

AbstractThis research aims to study the effect of quenching by oil with tempering at180°C and 400°C on wear rate of 100Cr6 steel. A pin-on-disc technique was used tomeasure wear rate at different loads and different sliding times with constant slidingspeed(2.199msec)and the hardness of steel dise was 45HRC.The results show that the wear resistance of the specimen quenched by oil andtempered at 400°C was more than the specimen quenched by oil and tempered at180°C.

الملخصيهدف البحث إلى د ا رسة تأثير التقسية بالزيت ثم إج ا رء الم ا رجعة عند درجات.100 Cr 400° على معدل البلى لفولاذ 6 C 180° و C ح ا رريةوقد استخدمت تقنيه المسمار على القرص لقياس معدل البلى عند تسليط أحمال مختلفة وفت ا رت.45HRC 2.199 ) وصلادة القرص الفولاذي msec) انزلاق مختلفة مع تثبيت سرعه الانزلاقوقد أظهرت النتائج ان معدل البلى يزداد مع زيادة الحمل المسلط والفترة الزمنية للانزلاق.وكذلك400° ذات مقاومه بلى C اظهرت النتائج ان العينه المقساة بالزيت والم ا رجعة عند درجه ح ا ررة.180°C أعلى بالمقارنة مع العينة المقساة بالزيت والم ا رجعة عند درجة ح ا ررة


Article
THE EFFECT OF TEMPERING ON THE FATIGUE BEHAVIOR FOR MEDIUM CARBON STEEL
تأثير الم ا رجعة لفولاذ متوسط الكربون على سلوك الكلال

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Abstract

AbstractThis research is concerned with the study of the effect of tempering on the fatigue strength ofmedium carbon steel (CK 45), by using different heat treatments including quenching in water andoil followed by tempering at (250, 450 & 650) oC comparisons between the effects of two mediumson microstructure, mechanical properties and fatigue strength for each quenching media . Thefatigue tests have been done under constant amplitude stresses with a stress ratio (R=-1). Theexperimental results reveal that water quenching followed by tempering at 250 oC (1 hr) givesmaximum fatigue strength for steel, and this is due to the formation of tempered martensite. Longfatigue cracks have been measured and studied from using fractography of fatigue specimens(SEM). Two models have been to proposed to assess fatigue lives of quenched and temperedmedium carbon steel at different tempering temperature . The first model was derived from thefatigue crack growth rate equation (da/dN) while the second model was extracted from the stressintensity factor equation (K) .

الخلاصةوالتقسية والم ا رجعة عند (Ck يهدف هذا البحث إلى د ا رسة تأثير مقاومة الكلال للفولاذ متوسط الكربون ( 45250 ) وذلك باستخدام المعاملات الح ا ررية المتضمنة التقسية (الإخماد) , 450, 650) oC درجات ح ا ررة مختلفةفي وسطين هما الماء والزيت متبوعا بالم ا رجعة عند درجات ح ا ررة المذكورة ، والمقارنة بين تأثير كل منالوسطين على البنى المجهرية الناتجة والخواص الميكانيكية وكذلك مقاومة الكلال لكل وسط تقسية. تم إج ا رءوالمعامل ح ا رريا عند اجهادات ثابتة السعة (as-received) اختبا ا رت الكلال للفولاذ غير المعامل ح ا رريا.( R = - وبنسبة إجهاد ( 11) أعطت أفضل مقاومة كلال للفولاذ hr) 250 oC أظهرت النتائج إن التقسية في الماء والم ا رجعة عندوذلك بسبب تكوين بنية المارتنسايت الم ا رجع، أما بالنسبة لوسط الزيت فكانت الظروف المثلى هي عند التقسية250 ، كما تم د ا رسة سلوك شقوق الكلال الطويلة من خلال صور المجهر oC في الزيت والم ا رجعة عندوقياس أطوال الشقوق لكل بنية مجهريه، وتم وضع أنموذجين رياضيين للتنبؤ بعمر (SEM) الالكتروني الماسحالكلال للفولاذ متوسط الكاربون المقسى في الماء والم ا رجع عند درجات ح ا ررية مختلفة اعتمادا على النتائجأما الثاني فتم استخ ا رجه من معامل شدة (da/dN) العملية حيث استخرج الأنموذج الأول من سرعة تقدم الشق. ( the stress intensity factor) (K) الإجهاد


Article
Modelling of Carburization Parameters Process for Low Carbon Steel

Authors: Abbas Khammas Hussein --- Laith Kais Abbas --- Jamal Jalal Dawood --- Nadeen Jaafar Ismae
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 6 Part (A) Engineering Pages: 1069-1079
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This paper representsthe carburization parameters for steel (1020) using Desirability Function Analysis-DFA. The experiments were conducted using Taguchi (L9) orthogonal array. Carburization parameters such as carburization temperature, carburization time and tempering temperature were optimized by multi - response considerations depending onmicrohardnessand were rate measurements. The optimal carburizing parameters had been determined by composite desirability value obtained from desirability function analysis while significant contribution of parameter was determined by analysis of variance (ANOVA). The analyses results showed that optimal combination for higher hardness and lower wear rate were at (A2=920 oC, B2= 3 hours and C3=120 oC). Confirmation test was also conducted to validate the test results. Mathematical models for composite desirability, microhardness and rate wear were determined. Experimental results showed that the carburization performance can be improved effectively through desirability approach.


Article
The Effect of Tempering Heat Treatment on Some Mechanical Properties of Medium Carbon Steel (AISI 1045) Formed By Cold Forging Process

Author: Raheem Abd Sayel Muhammad Al-Janabi
Journal: Univesity of Thi-Qar Journal مجلة جامعة ذي قار العلمية ISSN: 66291818 Year: 2018 Volume: 13 Issue: 3 Pages: 70-80
Publisher: Thi-Qar University جامعة ذي قار

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Abstract

Current paper discuses the effect of tempering as one of heat treatment processes on some mechanical properties of medium carbon steel (AISI 1045) such as hardness, ultimate tensile strength, yield strength and strain rate , formed by forging hammers operation as one of cold forging process .Three values of loads (20, 30 and 40 ) kg were used in forging operation .The results show that the tempering and cold hammering forging increase the ability of medium carbon steel (AISI 1045) to resist the internal stresses produced by hardening process , so the ultimate tensile strength and yield strength of tempered MCS 1045 decrease with an increase in tempering temperature .Otherwise, the strain rate and hardness of tempered MCS 1045 increases with an increasing of tempering temperature

البحث الحالي يناقش تأثير درجة حرارة المراجعة كواحدة من المعاملات الحرارية للصلب المتوسط الكاربون (فولاذ 45 ) المشكل بطريقة الحدادة بالقوالب المفتوحة ( المطارق ) ، اختيرت ثلاث درجات حرارية للمراجعة ( 200 ، 400 و 600 ) درجة حرارية ، مع اختيار ثلاثة احمال لمطرقة ميكانيكية ( 20 ، 30 و 40 ) كغم ، تم تحضير عينات الشد ومراجعتها وطرقها ومن ثم تمت عمليات حساب اقصى اجهاد شد وحمل الخضوع وكمية الانفعال ومقدار الصلادة ، توصل البحث الى ان عملية التشكيل بالحدادة تكسب المادة الهندسية متانة اكبر واجهاد شد اقصى بأستخدام عملية المراجعة وخاصة في درجات الحرارة المنخفضة .


Article
Duplex Inhibition of CO2 Corrosion in Iraqi Oilfield

Author: Sami I.J. Al-rubaiey
Journal: University of Thi-Qar Journal for Engineering Sciences مجلة جامعة ذي قار للعلوم الهندسية ISSN: 26645564/26645572 Year: 2011 Volume: 2 Issue: 3 Pages: 74-94
Publisher: Thi-Qar University جامعة ذي قار

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Abstract

New method for inhibition CO2 corrosion in Iraqi oilfield was used in this work. This new method included using combination of heat treatment of steel and added Aromatic (Tetrahydronaphthalene) compounds as corrosion inhibitor in different concentration (0.05%,0.1%, 0.2%, 0.5% and 1%). The results referred that the weight loss was reduced as inhibitor concentration increased for all conditions of specimens whether, there were heat treated or not. The combination of annealing heat treatment of samples and using Aromatic compoundsinhibitor offered a better corrosion resistance than the combination of quenching + tempering (Q+T) samples. The presence of inhibitor improves the corrosion resistance for annealed samples. For fully annealing, the weight loss was 5 times lesser than that for (Q+T) samples,while the weight loss of steel (as received condition) was 3 times lesser than that for (Q+T)samples.

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