Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : low alloy steel

Enhance Corrosion Resistance of T22 Alloy by Adding of La3O2 Nanoparticles; Condition of Oil Flow

A.A. Al-Attar

Engineering and Technology Journal, 2017, Volume 35, Issue 9, Pages 936-942

T22 low alloy steel is represented as one of the best alloy using to production oil pipe, patrol valves, high temperature applications. This alloy has good mechanical properties, a satisfaction corrosion resistance and acceptable thermal conductivity at nature conditions. At high pressure applications with rapid flow of a fluid stream, T22 alloy is suffered severe degradation or corrosion. Though in an attempt to reduce the damage caused by corrosion, it has been resorting to the addition of La3O2, that is working on created a composition phase and a protective layer of corrosion. Where they were mixing alloy elements powders with different amount of La3O2 nanoparticles. mixed powder was prepared by powder metallurgy PM method and using a press at compression strength 175 MPa in mold steel cylindrical shape die, mold diameter is 20 mm and a height of 100 mm, sintering process has been done at a temperature 1200 °C and using Argon gas as inert gas. X-ray diffraction examination was used to identify the phases formed and microscopic structure of samples after sintering was also examined using scanning electron microscope, Archimedes method was examined to measured density and porosity of sintered samples. The examination of erosion corrosion has used a private system and thus adopted the corrosive sea water as a medium. Erosion corrosion test results showed clearly increased corrosion resistance with increasing of La3O2 amount, due to existence resistance to corrosion phase. 10 vol.% of La3O2 nanoparticles is the best nanoadditives amount which support a good resistance to erosion corrosion.

Effect of Thermally Sprayed Ceramic Coating on Properties of Low Alloy Steel

Fadhil A. Chyad; Abdalkalaq F. Hamood; Lamees S. Faiq

Engineering and Technology Journal, 2014, Volume 32, Issue 10, Pages 2568-2575

Thermal spraying technique was employed for coating low alloy steel specimens that have been used in a derrick oil well frames.
Two types of ceramic materials were used as a coating material and two groups of steel samples were prepared for coating process.
The first group was coated by zirconia while the second group was coated by alumina. Ni-Al composite powder was used forbonding the coating material on the substrate surface of the steel specimens.
The hardness, adhesion strength of the coating layers as well as wear rateswere studied for the two steel group samples and compared with as received steel.
The results showed an increase in the mechanical properties with a decrease in wear rate values for coated samples as compared to those of uncoated samples.

Effect of Normalizing Process on Mechanical Properties of Submerged-arc Weldment

Abbas Sheyaa Alwan

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1554-1562

Submerged arc welding is carried out and efficient metal- joining process widely
used in great importance in many industrial applications, structures of ships, storage
tanks and agriculture equipments. Low alloy steel used under welding conditions
which are, (560 Amp) welding current, (42cm/min) welding speed, (3.25mm) wire
diameter, direct current straight polarity (DCSP) with the joint geometry of single -Vbutt
joint and weld one pass are used for plate of thickness 16mm. After welding, the
components have be submitted to a normalization heat treatment in order to recover
the original mechanical properties of the welds. In this work two different filer metals
both in the as welded condition and after normalizing heat treatment have been studied.
Optical microscopy was used to observe the weld microstructure. Tensile and Charpy
V toughness testing and microhardness measurements were used to evaluate the
mechanical properties of joint. Results show that normalizing reduces the original
columnar structure in the as welded condition to an equiaxial structure. It was observed
a high decrease in the tensile properties specially the yield strength after normalizing.
In respect of toughness, the normalizing heat treatment was observed to increase the
Charpy V energy.

One Parameter Composite Semigroups of Linear Bounded Operators in Strong Operator Topology of Schatten Class Cp

Samir Kasim Hassan; Al-Taie M; Al-Malki Anam; Al-Attar Abeer; Mustafa Khaleel Ismael; Fatema Ahmed Sadeq; Radhi A .Zboon; Jehad R.Kider; Samir K .Hassan; Hussain J. M. Alalkawi; Raad H. Majid; Rawaa A. Alomairy; Luma Abdul Ghani Zghair; Hadia Kadhim J.Al-Ogili; Assifa M. Mohamad; Abbas Sheyaa Alwan; Haider L. Aneed; Assim H Yousif; Salema Sultan Salman; Abbas Hussien Miry; Abduladhem A.Ali; Mohammed Zeki Al-Faiz; Sabah N. mahmood; Khansaa Dawood Selman; Shaymaa Tareq Kadhim

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1463-1470

For semigroups of linear bounded operators on Hilbert spaces, the problem of
being in Cp , 0 Keywords

Effect of Pack Cementation Coating on Hot Corrosion Resistance of Low Alloy Steel

Jawad Badr Gatea; Muna khedier Abbass

Engineering and Technology Journal, 2009, Volume 27, Issue 2, Pages 332-346

Two technique of coatings were performed by applying pack cementation
technology, the first one was aluminizing diffusion coated low alloy steel substrate
whereas the second one was single step simultaneous Co-deposition silicon- aluminum
diffusion coated low alloy steel substrate. The pack mixture used for producing both
coating systems in pack cementation process was composed of (30% Al, 2% NH4Cl and
the filler 68% Al2O3) , (30% Al , 5% Si , 2% NH4Cl and 63% Al2O3 ) respectively. The
pack temperature was 1000◦C and the diffusion time was 3 hr. XRD exhibits the phases
formed on both coated systems are Fe2Al5 , FeAl3 and FeSi . Uncoated low alloy steel
substrate and the both two coating systems were subjected to exposure environment
deposit salts mixture of (50%Na2SO4 and 50%NaCl) with weight (2mg /cm2), using
cyclic oxidation method in the experiments at temperature of 750◦C for 100hr each
cycle of 5hr. It was found that the oxidation kinetic for uncoated low alloy steel will give
evidence that the oxides formed on this alloy are non – protective. The XRD analysis
exhibited the phases are Fe2O3 , Fe3O4. It was found they followed linear rate law, and
spalling was observed. After these hot corrosion tests were undertaken, It was found that
the oxidation kinetics for both coated systems in environment consist of salt mixture
(50% NaCl +50% Na2SO4) followed parabolic law (protective oxidation behavior). XRD
exhibits the oxides formed on both coated systems are Al2O3, SiO2.