پلاستیک ها، الاستومر ها و کامپوزیت ها به منظور کنترل خوردگی

 Using Plastics, Elastomers, and Composites for Corrosion Control

استفاده از پلاستیک ها، الاستومر ها و کامپوزیت ها به منظور کنترل خوردگی 

ABSTRACT

This chapter provides a broad overview of the application of polymers used for corrosion control in the chemical proces- sing industry. The generalizations offered about polymer performance might suggest possible approaches, but they should not be considered as recommendations owing to the complexity of equipment design and the many variables of chemical processing. Consultations with experts, analyses of case histories, and testing are essential to the success of these materials.

 

خستگی خوردگی در آلیاژ آلومینیوم – منیزیم بسیار ریزدانه

A microscopic study on the corrosion fatigue of ultra-fine grained

and conventional Al–Mg alloy

مطالعه میکروسکوپی خستگی خوردگی در آلیاژ آلومینیوم – منیزیم بسیار ریزدانه و مرسوم

ABSTRACT

The corrosion behavior of a nanocrystalline (NC)/ultrafine grained (UFG) Al–Mg based alloy was investigated and compared to its conventional counterpart 5083(H111). The corrosion fatigue (CF) was studied with respect to pit initiation, pit location and crack propagation as a function of environment. Scanning electron microscopy (SEM) with EDS was used to analyze the fracture surface of the failed specimen with respect to pitting characteristics, crack propagation and corrosion product. Load vs. cycles to failure was measured and S/N curves were generated for the UFG Al–Mg based alloy and the conventional counterpart 5083 in air and seawater.

 

تحقیق روی رفتار خوردگی اتصالات لحیم کاری مس

Investigation on Corrosion Behaviour of Copper Brazed Joints 

تحقیق روی رفتار خوردگی اتصالات لحیم کاری مس

ABSTRACT

DHP (Deoxidized High Phosphorus(copper is widely used in various heat transfer units such as, air conditioners, refrigerators, evaporators and condensers. Copper sheets and tubes (ISODHP) were brazed with two different brazing alloys. Corrosion resistances of the joints were examined by polarization test. The selected fillers consisted of a silver-based brazing alloys (hard solder); AWS-BCu5, and a copper-based filler AWS BCuP2. All the joints were brazed utilizing two different brazing processes including furnace brazing under argon and air atmosphere. All of the fillers were used with and without flux. The microstructure of the brazed sheets was examined using both optical and scanning electron microscope (SEM). Hardness and leak tests were carried out on all the brazed tubes. In all brazing alloys selective and galvanic corrosion were observed in filler metals, but in copper phosphor alloys the copper adjacent to the joints were noticeably corroded by pitting method. It was found that the samples brazed with BAg5 filler metal using argon furnace show a higher resistance to corrosion. They also have a good ductility in the brazed zone.

 

رفتار خستگی خوردگی آلیاژ آلومینیوم جوشکاری شده

Corrosion fatigue behaviour of aluminium alloy 6061-T651 welded

using fully automatic GMAW and ER5183 filler alloy

رفتار خستگی خوردگی آلیاژ آلومینیوم 6061-T651 جوش داده شده با (GMAW)

با آلیاژ ER5183 به عنوان فیلر

ABSTRACT

The fatigue life of aluminium 6061-T651 at various applied stress amplitudes in the unwelded and welded condition was found to be significantly reduced on immersion in a 3.5% NaCl simulated sea water solution, compared to that measured in ambient air. The ratio of fatigue life in NaCl test solution to that in air increased as the stress amplitude decreased. The observed reduction in the fatigue life in the NaCl test solution was most likely due to the presence of pits which nucleated on second phase particles or precipitates. Welded joints performed using pulsed gas metal arc welding and ER5183 filler wire failed at the interface between the weld metal and the heat-affected zone as a result of a high pitting rate in this region.

 

خوردگی ترک تنشی بر روی خطوط انتقال گاز

Stress-Corrosion Cracking On Gas-Transmission Pipelines

history, causes, and mitigation

خوردگی ترک تنشی بر روی خطوط انتقال گاز :

تاریخچه، علل ایجاد و راه های کاهش خطرات

ABSTRACT

This paper reviews the historical data concerning external stress-corrosion  cracking (SCC) of gas transmission pipelines as it has evolved since 1965 and the factors controlling such SCC (eg, pipe environment, steel, and operation). Discussion of these Factors leads to identification of ways in which this cracking can be controlled / mitigated – in the practical setting of an operating pipeline that is expected to provide a reasonable return on equity.

 

آندایزینگ و عملیات حرارتی تیتانیوم متخلخل

Effects of anodizing parameters and heat treatment on 

nanotopographical features, bioactivity, and cell culture 

response of additively manufactured porous titanium 

اثر پارامترهای آندایزینگ و عملیات حرارتی بر نانو عوارض سطحی، زیست‌فعالی

و پاسخ کشت سلول در تیتانیوم متخلخل ساخته‌شده به روش افزایشی

ABSTRACT

Anodizing could be used for bio-functionalization of  the surfaces of  titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20 V anodizing time: 30 min to 3 h) are used for anodizing porous titanium  structures that were later heat treated at 500o  C. The nanotopographical features are examined  using electron microscopy while the bioactivity of anodized surfaces is measured using  immersion tests in the simulated body fluid (SBF).

 

مبانی لایه نشانی شیمیایی بخار (CVD)

Fundamentals of Chemical Vapor Deposition

مبانی لایه نشانی شیمیایی بخار (CVD)

ABSTRACT

Chemical vapor deposition is a synthesis process in which the chemical constituents react in the vapor phase near or on a heated substrate to form a solid deposit. The CVD technology combines several scientific and engineering disciplines including thermody- namics, plasma physics, kinetics, fluid dynamics, and of course chemistry. In this chapter, the fundamental aspects of these disci-plines and their relationship will be examined as they relate to CVD.

 

مقاومت به فرسایش و اکسیداسیون پوشش SiC برای کامپوزیت های کربن- کربن

Oxidation and ablation resistance of ZrB2–SiC–Si/B-modified

SiC coating for carbon/carbon composites

مقاومت به فرسایش و اکسیداسیون پوشش SiC اصلاح شده با ZrB2-SiC-Si/B

برای کامپوزیت های کربن/ کربن

ABSTRACT

ZrB2–SiC–Si/B-modified SiC coating was prepared on the surface of carbon/carbon (C/C) composites by two-step pack cementation. The coating could efficiently provide protection for C/C composites from oxidation and ablation. The improvement of oxidation resistance was attributed to the self-sealing property of the multilayer coating. A dense glassy oxide layer could afford the high temperature up to 2573 K and efficiently protect C/C composites from ablation.

جلوگیری از خوردگی فولاد کربنی در حین اسیدشویی

Corrosion inhibition of carbon steel during acid pickling

جلوگیری از خوردگی فولاد کربنی در حین اسیدشویی

ABSTRACT

A novel cationic surfactant, N-(2-(2-mercaptoacetoxy)ethyl)-N,N-dimethyl dodecan-1-aminium bromide), has been synthesized to study its corrosion inhibiting effect against carbon steel in 1.0 M HCl solution. The corrosion inhibition efficiency was measured by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss methods. The inhibition efficiencies obtained from these methods were in good agreement. The inhibition efficiency slightly decreased in the temperature range 30–60 °C. The synthesized inhibitor acted as a mixed inhibitor. Thermodynamic adsorption and activation parameters were discussed. Adsorption of the synthesized inhibitor was found to follow the Langmuir adsorption isotherm. A chemical adsorption mechanism is proposed.

 

انتخاب پوشش Coating Selection

Coating Selection

انتخاب پوشش

ABSTRACT

An improved approach to coating selection should thus allow progressive elimination and lend itself to a computerised implementation. Furthermore, an approach which avoids the identification of one dominant wear mechanism would be desirable. A systematic framework fulfilling these goals is described below. This is intended to provide a basis for minimising the probability of tribological problems by indicating the material property limitations and characteristics needed (Matthews et. al., 1992b).