پایلوت پلنت های آزمایشی HIsarna Pilot Plant Project

HIsarna Pilot Plant Project

پروژه ماشین آلات آزمایشی به روش HIsarna

ABSTRACT

HIsarnaTM represents a new phase in the  global direct smelting development cycle.  It is,  in essence, a merger between Tata Steel- developed smelt cyclone technology and HIsmelt TM (Rio Tinto)-developed bath smelting  technology.  A pilot plant at IJmuiden,  Netherlands with a nominal capacity of 60,000  t/a is nearing completion and is due to start shortly. 

The catalyst that brought these technologies  together and made the pilot plant project  possible is ULCOS.  The key driver from this  perspective is efficient, cost-effective carbon  dioxide collection for potential geological  storage. HIsarna’s inherently simple, once- through gas flow path provides an easy carbon  dioxide collection option without the need for a carbon dioxide scrubber. 

 

جوشکاری اینکونل 625 و فولاد زنگ‎نزن L 304 با پرتوی الکترونی

Microstructure and hardness studies of electron beam

welded Inconel 625 and stainless steel 304L

مطالعه ریزساختار و سختی اینکونل 625 و فولاد زنگ‎نزن L 304

جوشکاری شده با پرتوی الکترون

ABSTRACT

In this study, electron beam welding of dissimilar Inconel 625 and SS 304L alloys was successfully performed by employing optimized electron beam welding parameters. The welded joint was characterized using SEM/EDS, XRD and micro-hardness tester. The welded joint was found homogeneous, well bonded and defect free. Two types of microstructure i.e. columnar dendritic and cellular dendritic were observed in the fusion zone. The development of different microstructures in the fusion zone was attributed to the localized cooling effects during solidification. Few micro-cracks along with dendrites splitting were observed in the vicinity of end crater that was mainly due to the segregation of S element. A significant variation of Ni and Fe was observed across Inconel/FZ and FZ/SS interfaces due to their fast diffusion in the melt pool. Micro-hardness measurements across Inconel/FZ and FZ/SS interfaces showed an increasing trend in the FZ from SS 304L towards Inconel base alloy.

 

سنتز نانو ورقه های ZnO از طریق روش الکترورسوبی

Synthesis of ZnO nanosheets via electrodeposition method and

their optical properties, growth mechanism

سنتز نانو ورقه های ZnO از طریق روش الکترورسوبی ، خواص نوری و مکانیزم رشد

ABSTRACT

ZnO nanosheets were prepared by electrochemical deposition method at 80 C on seeded Indium Tin Oxide conducting glass substrates. The seed layer was coated on ITO by spin coating and annealed at 350 C for 30 min prior to electrochemical deposition growth. X-ray diffraction patterns (XRD) and field emission scanning electron microscope (FESEM) images confirmed that the ZnO nanosheets consist of polycrystalline structures. Room temperature photoluminescence spectra (PL) of the ZnO nanosheets exhibited band-edge ultraviolet (UV) and visible emission (blue) indicating the ZnO nanosheets had excellent optical properties. The UV–Vis absorption spectrum of ZnO nanosheets was shown a strong absorption at 300 nm. The ZnO nanosheets structure demonstrated higher photocatalytic activity during degradation of aqueous methylene blue under visible-light irradiation. Moreover, the growth mechanism of the ZnO nanosheets had been discussed.

 

اثر نرخ سرد شدن روی ساختار میکروسکوپی آلیاژ هایپر یوتکتیک Al-Ni

The influence of cooling rate on the microstructure of an Al–Ni hypereutectic alloy

اثر نرخ سرد شدن روی ساختار میکروسکوپی آلیاژ هایپر یوتکتیک Al-Ni

ABSTRACT

An Al–4 at.% Ni alloy was prepared by a melt spinning technique and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and high resolution transmission electron microscopy. The resulting ribbon microstructure consists of intermetallic Al9Ni2 globular-like structures embedded within an aluminum matrix. Characteristic globules are nanometric (∼100 nm) and are mainly located at the grain boundaries. The resulting effect on the mechanical properties is the enhancement of the alloy hardness from 58 to 371 HV.

 

خزش در فلزات آمورف (شیشه فلزات) Creep in amorphous metals

Creep in amorphous metals

خزش در فلزات آمورف (شیشه فلزات)

ABSTRACT

This paper reviews the work on creep behavior of amorphous metals. There have been, overthe past several years, a few reviews of the mechanical behavior of amorphous metals. Ofthese, the review of the creep properties of amorphous metals by Schuh et al. though oldestof the three, is particularly noteworthy and the reader is referred to this article publishedin 2007. The current review of creep of amorphous metals particularly focuses on thoseworks since that review and places the work prior to 2007 in a different context where newdevelopments warrant.

 

اثر سرعت جوشکاری بر تنش پسماند در طول جوشکاری قوس با الکترود تنگستن تحت پوشش گاز

Influence of welding speed and power on residual stress during gas tungsten arc welding (GTAW) of thin sections

with constant heat input: A study using numerical simulation and experimental validation

اثر سرعت جوشکاری و توان بر تنش پسماند

در طول جوشکاری قوسی الکترود تنگستن (GTAW) مقاطع نازک با ورودی گرمای ثابت

مطالعه ای با استفاده از شبیه سازی و اعتبارسنجی تجربی

ABSTRACT

The temperature distribution and residual stresses for a GTAW circumferential butt joint of AISI 304 stainless steel using numerical simulation have been evaluated. For evaluation of weld induced residual stresses, the analysis of heat source fitting was carried out with heat inputs ranging from 200 to 500 J/mm to arrive at optimal heat input for obtaining proper weld penetration and heat affected zone (HAZ). For this chosen heat input, the influence of different weld speeds and powers on the temperature distribution and the residual stresses is studied. The heat source analysis revealed the best choice of heat input as 300 J/mm. The residual stresses on the inner and outer surfaces, and along the radial direction were computed. Increase in temperature distribution as well as longitudinal and circumferential residual stresses was observed with the increase in weld speed and power. The validity of the results obtained from numerical simulation is demonstrated with full scale shop floor welding experiments.

 

رفتار استحاله سرد شدن پیوسته فولاد خط لوله‎ی X70

Continuous cooling transformation behavior of X70 pipeline steel

رفتار استحاله سرد شدن پیوسته فولاد خط لوله‎ی X70 

ABSTRACT

The comprehensive mechanical properties of steel depended on the final microstructure and grain refinement. In order to obtain high performance pipeline steel, composition design and the application of controlled rolling and controlled cooling technology had become a key, especially the latter which had decisive influence on the product’s final texture and comprehensive performance in modern iron and steel material production. Along with the development of the modern rolling equipment as well as the in-depth study of controlled rolling and controlled cooling technology, the application of controlled rolling and controlled cooling technology had become an important means of fully excavating the potential of the material properties based on the existing material chemical compositions and it had got the extensive attention from modern iron and steel materials research field.

غرق شدن تایتانیک بعلت مشکل متالورژیکی

RMS Titanic: A Metallurgical Problem

آر ام اس تایتانیک : یک مشکل متالورژیکی

ABSTRACT

On 14 April 1912, at 11:40 p.m., Greenland Time, the Royal Mail Ship Titanic on its maiden voyage was proceeding westward at 21.5 knots (40 km/h) when the lookouts on the foremast sighted a massive iceberg estimated to have weighed between 150,000 to 300,000 tons at a distance of 500 m ahead. Immediately, the ship’s engines were reversed and the ship was turned to port (left) in an attempt to avoid the iceberg. In about 40 seconds, the ship struck the iceberg below the waterline on its starboard (right) side near the bow. The iceberg raked the hull of the ship for 100 m, destroying the integrity of the six forward watertight compartments. Within 2 h 40 min the RMS Titanic sank.

Metallurgical examination and chemical analysis of the steel taken from the Titanic revealed important clues that allow an understanding of the severity of the damage inflicted on the hull. Although the steel was probably as good as was available at the time the ship was constructed, it was very inferior when compared with modern steel. The notch toughness showed a very low value (4 joules) for the steel at the water temperature (−2 °C) in the North Atlantic at the time of the accident.

 

تاثیر فرایند تمپر بر ساختار و خواص مکانیکی فولاد HSLA-100

Influence of tempering on the microstructure and

mechanical properties of HSLA-100 steel plates

تاثیر فرایند تمپر بر ریزساختار و خواص مکانیکی صفحات فولادی HSLA-100

ABSTRACT

The influence of tempering on the microstructure and mechanical properties of HSLA-100 steel (with C-0.04, Mn-0.87, Cu-1.77, Cr-0.58, Mo-0.57, Ni-3.54, and Nb-.038 pct) has been studied. The plate samples were tempered from 300 °C to 700 °C for 1 hour after austenitizing and water quenching. The transmission electron microscopy (TEM) studies of the as-quenched steel revealed a predominantly lath martensite structure along with fine precipitates of Cu and Nb(C, N). A very small amount of retained austenite could be seen in the lath boundaries in the quenched condition. Profuse precipitation of Cu could be noticed on tempering at 450 °C, which enhanced the strength of the steel significantly (yield strength (YS)—1168 MPa, and ultimate tensile strength (UTS)—1219 MPa), though at the cost of its notch toughness, which dropped to 37 and 14 J at 25 °C and −85 °C, respectively. The precipitates became considerably coarsened and elongated on tempering at 650 °C, resulting in a phenomenal rise in impact toughness (Charpy V-notch (CVN) of 196 and 149 J, respectively, at 25 °C and −85 °C) at the expense of YS and UTS. The best combination of strength and toughness has been obtained on tempering at 600 °C for 1 hour (YS-1015 MPa and UTS-1068 MPa, with 88 J at −85 °C)

 

کامپوزیت‎های تقویت شده با الیاف سه بعدی فیبر شیشه-پلی پروپیلن

Polypropylene/glass fibre 3D-textile reinforced composites

for automotive applications

کامپوزیت‎های تقویت شده با الیاف سه بعدی فیبر شیشه/پلی پروپیلن

برای کاربردهای خودرو

ABSTRACT

Textile-reinforced thermoplastic composites offer huge application potentials for a rapid manufacturing of components with versatile possibilities of integrating functions. However, an application of these new materials requires the knowledge of the directional dependent material properties. In this study, results are presented concerning selected relevant load cases for industrial applications. For the new group of multi-layered flat bed weft-knitted glass fibre/polypropylene composites (MKF-GF/PP), tensile tests under different temperatures and test velocities have been carried out as well as Charpy impact tests, open hole tension tests and dynamic-mechanical analysis. The mechanical properties of MKF-GF/PP and unidirectional GF/PP composites with tailored fibre surface and interphase, respectively, have been compared to those of woven GF/PP composites and GF/PP composites made of non-crimp fabrics (NCF) as a benchmark.