scholarly journals Research on NDT Technology in Inference of Steel Member Strength Based on Macro/Micro Model

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Beidou Ding ◽  
Naiqiang Xiao ◽  
Shuxun Zhang ◽  
Yong Wang
Keyword(s):  
Grain Size ◽  
Regression Analysis ◽  
Chemical Composition ◽  
Carbon Steel ◽  
Quantitative Relationship ◽  
Engineering Practice ◽  
Composition Analysis ◽  
Chemical Compositions ◽  
Steel Strength ◽  
Tension Properties

In consideration of correlations among hardness, chemical composition, grain size, and strength of carbon steel, a new nondestructive testing technology (NDT) of inferring the carbon steel strength was explored. First, the hardness test, chemical composition analysis, and metallographic analysis of 162 low-carbon steel samples were conducted. Second, the following works were carried out: (1) quantitative relationship between steel Leeb hardness and carbon steel strength was studied on the basis of regression analysis of experimental data; (2) influences of chemical composition and grain size on tension properties of carbon steel were analyzed on the basis of stepwise regression analysis, and quantitative relationship between conventional compositions and grain size with steel strength was obtained; (3) according to the macro and/or micro factors such as hardness, chemical compositions, and grain size of carbon steel, the fitting formula of steel strength was established based on MLR (multiple linear regressions) method. The above relationships and fitting formula based on MLR method could be used to estimate the steel strength with no damage to the structure in engineering practice.

Study on the Effect on Sintering Mineralization of Iron Ore

2013 ◽  
Vol 652-654 ◽  
pp. 2538-2542 ◽  
Author(s):  
Xiao Hui Fan ◽  
Ying Li ◽  
Xu Ling Chen
Keyword(s):  
Grain Size ◽  
Regression Analysis ◽  
Chemical Composition ◽  
Iron Ore ◽  
Raw Material ◽  
Sintering Process ◽  
Main Effect ◽  
Relationship Model ◽  
Ore Mineralization ◽  
The Relationship

The main effect on iron ore mineralization performance in the sintering process is the grain size of raw material and chemical composition. The results show that -0.5mm particles can mineralize, but +0.5mm particles remain a nucleus in sinter. This paper analyses the effect of the chemical composition on mineralization characteristics of liquid production. The relationship model is established by using regression analysis between the chemical composition and liquid formation characteristics. The mian factors of mineralization in the chemical composition: SiO2, CaO, MgO and Al2O3.

scholarly journals Investigation of the Resistance and Sensitivity of Infectious Bacteria to Dendrostellera lessertii and Chemical Composition Analysis

2021 ◽  
Vol 6 (1) ◽  
pp. 30-36
Author(s):  
Mostafa Alamholo
Keyword(s):  
Chemical Composition ◽  
Methanolic Extract ◽  
Antibacterial Properties ◽  
Gas Chromatography Mass Spectrometry ◽  
Total Phenolic ◽  
Dilution Method ◽  
Composition Analysis ◽  
Chemical Compositions ◽  
Root Extract ◽  
Chemical Composition Analysis

Introduction: Herbal plants are important sources for finding new and rare products of medicinal value for drug development. The present research aimed to investigate the antibacterial properties of Dendrostellera lessertii against infectious bacteria and analyze its chemical composition. Methods: The different organs comprising root, stem, and leaf of D. lessertii from Lorestan province, Iran, were tested. Antibacterial activity was assessed using the agar well-diffusion assay. The total phenolic content (TPC) and total flavonoid content (TFC) were assessed by the Folin Ciocalteu and aluminum chloride methods, respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were tested by the serial dilution method, and chemical compositions were analyzed by gas chromatography-mass spectrometry (GC/MS). Results: The chemical composition analysis showed the dominance of bergamotol (10.62%) and bis (2-ethylhexyl) phthalate (7.49%) in the stem extract. However, phytol (12.64%) and E-11-hexadecenal (12.53%) were major constituents in the root extract. Furthermore, major constituents in the leaf extract were phytol (19.658%) and hexadecanoic acid (7.151%). The methanolic extract of root exhibited the highest TPC as 109.1±2.2 mgGA/g and TFC as 2.1±0.33 mgQ/g. The root methanolic extract demonstrated a MIC of 3.125 mg/mL against Enterococcus faecalis. Accordingly, the highest sensitivity and resistance were observed on E. faecalis and Pseudomonas aeruginosa, respectively. Conclusion: Dendrostellera lessertii extract is suggested as a source for antimicrobial drugs, especially to treat bacterial infections.

scholarly journals Comparison of colors, microstructure, chemical composition and thermal properties of bamboo fibers and parenchyma cells with heat treatment

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Jieyu Wu ◽  
Tuhua Zhong ◽  
Wenfu Zhang ◽  
Jiangjing Shi ◽  
Benhua Fei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Properties ◽  
Chemical Composition ◽  
Lignin Content ◽  
Treatment Temperature ◽  
Composition Analysis ◽  
Chemical Compositions ◽  
Cellulose Content ◽  
Parenchyma Cells ◽  
Bamboo Fibers

AbstractThe effects of heat treatment at various temperatures on mechanically separated bamboo fibers and parenchyma cells were examined in terms of color, microstructure, chemical composition, crystallinity, and thermal properties. The heat-treated parenchyma cells and fibers were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), chemical composition analysis, and thermogravimetric analysis (TGA). The results revealed that the colors of bamboo fibers and parenchyma cells were darkened as treatment temperature increased. The microstructure of the treated fibers and parenchyma cells slightly changed, yet the shape of starch granules in parenchyma cells markedly altered at a temperature of above 160 °C. The chemical compositions varied depending on the heat treatment temperature. When treated at 220 °C, the cellulose content was almost unchanged in fibers but increased by 15% in parenchyma cells; the hemicellulose content decreased and the lignin content increased regardless of fibers and parenchyma cells. The cellulose crystal structure was nearly unaffected by heat treatment, but the cellulose crystallinity of fibers changed more pronouncedly than that of parenchyma cells. The thermal stability of parenchyma cells after heat treatment was affected more substantially compared to fibers.

The Discrepancy between Gross Features and Chemical Compositions in Gallbladder Stone: A Descriptive Single Center Study in the United Arab Emirates

2021 ◽  
Vol 02 ◽  
Author(s):  
Byung Hyo Cha ◽  
Min Jung Park ◽  
Joo Yeong Baeg ◽  
Sunpyo Lee ◽  
Young Joon Ahn ◽  
...  
Keyword(s):  
Chemical Composition ◽  
United Arab Emirates ◽  
Gastrointestinal Disease ◽  
Chemical Constituents ◽  
Composition Analysis ◽  
Cholesterol Stone ◽  
Chemical Compositions ◽  
Gallbladder Stone ◽  
Tertiary Referral Hospital ◽  
Primary Indication

Background and Study Aim: Gallbladder stone (GBS) is a common gastrointestinal disease that is the primary indication for cholecystectomy. The present study was conducted to describe the chemical composition of gallstones in a tertiary referral hospital in the United Arab Emirates. Materials and Methods: Patients diagnosed with GBS and who underwent cholecystectomy due to symptomatic GBS and cholecystitis in Sheikh Khalifa Specialty Hospital were enrolled in this study. After cholecystectomy, all stone specimens were classified according to their gross findings into 4 groups, namely black pigmented stones (BLPS), brown pigmented stones (BRPS), mixed cholesterol stones, and cholesterol stones (CLS). Quantitative analysis using Fourier transform infrared spectroscopy was then performed to define the stones’ chemical constituents. They were reclassified into two groups as CLS (cholesterol ≥ 60%) and pigmented stones (PGS, cholesterol ≤ 59%) based on gallstone composition analysis. Results: A total of 237 stones were divided into four groups based on their gross findings; cholesterol stones (32.0%), mixed cholesterol (29.2%), black pigmented (26.4%), and brown pigmented (12.3%). After chemical composition analysis, they were resorted into the two following groups according to their cholesterol proportions: pigmented (28.3%) and cholesterol (71.7%). There were significant statistical mean age differences between the pigmented and cholesterol stone groups (58.5±19.8 vs. 34.4±11.0, p < 0.01). Conclusion: This descriptive study showed the hospital-based clinical incidence of GBS and suggested that there might be a discrepancy in stone classification based on gross findings and chemical compositions. Moreover, pigmented stones are more likely to be present in older patients than cholesterol stones.

Chemical Composition Analysis of TiAlBN Nanocomposite Coating Deposited via RF Magnetron Sputtering

2013 ◽  
Vol 594-595 ◽  
pp. 551-555 ◽  
Author(s):  
Zulkifli Mohd Rosli ◽  
Zainab Mahamud ◽  
Wai Loon Kwan ◽  
Jariah Mohamad Juoi ◽  
K.T. Lau
Keyword(s):  
Chemical Composition ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Boron Concentration ◽  
Rf Magnetron Sputtering ◽  
Nanocomposite Coating ◽  
Composition Analysis ◽  
Chemical Compositions ◽  
Aisi 316 ◽  
Substrate Temperatures

TiAlBN nanocomposite coating have been successfully deposited on AISI 316 substrate via RF magnetron sputtering by varying nitrogen-to-total flow ratio (RN) of 5, 15, 20, 25%, as well as varying substrate temperature of 100, 200, 300, and 400 oC; using single Ti-Al-BN hot-pressed target. Chemical compositions of the coatings were analysed using X-ray photoelectron spectroscopy (XPS). XPS results showed that the TiAlBN nanocomposite coating reaches a nitride saturated state at higher RN(e.g 15, 20, and 25%) and boron concentration was found to be approximately 9 at.%. However, as the concentration of nitrogen decreases at lower RN(5%), boron concentration was found to increase to 16.17 at. %.This is due to the increase of TiB2phase in the coating. Variations of substrate temperatures were found to give no significant effect on the chemical composition of the deposited TiAlBN nanocomposite coating.

Effect of Alloying Elements on Microstructure, Texture Development, and Mechanical Properties of Magnesium Alloys

2012 ◽  
Vol 217-219 ◽  
pp. 382-385 ◽  
Author(s):  
Chang Wan Ha ◽  
Sung Ji Choi ◽  
No Jin Park
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Chemical Composition ◽  
Magnesium Alloy ◽  
Shear Band ◽  
Tensile Test ◽  
Magnesium Alloys ◽  
Chemical Compositions ◽  
Basal Texture ◽  
Hot Rolled

In this study, the magnesium alloys AZ31, ZK10, and ZEK100 are investigated through microstructure, texture, and tensile test. The sheets were hot rolled, and different results were found for different chemical compositions. The contained elements affected the grain size, shear band, twins, and intensity of the basal texture of the magnesium alloy. Thus, if a magnesium sheet had finer grains and a weak (00.1) texture because of its chemical composition, it had the most favorable formability.

scholarly journals Effect of Alloying Additives and Microadditives on Hardenability Increase Caused by Action of Boron

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 589
Author(s):  
Beata Białobrzeska
Keyword(s):  
Grain Size ◽  
Chemical Composition ◽  
Critical Diameter ◽  
Chemical Compositions ◽  
Austenitizing Temperature ◽  
Alloying Additives ◽  
Jominy Test ◽  
Variable Chemical ◽  
Full Annealing ◽  
Ideal Critical Diameter

The presented work was aimed at evaluating influence of boron on hardenability of steel quantitatively and evaluating this effect during complex use of boron with other alloying additives like chromium, vanadium and titanium. For this purpose, eight melts with variable chemical compositions were prepared. From the ingots, cylindrical specimens with normalized dimensions according to EN ISO 642:1999 were cut out and subjected to full annealing at 1200 °C and to normalizing at 900 °C. Such specimens were subjected to the hardenability Jominy test. In order to distinguish the influence of boron on hardenability of a given melt and thus to eliminate the differences resulting from its chemical composition, grain size and austenitizing temperature, the obtained ideal critical diameter was corrected and the boron effectiveness factor was determined. The performed examinations and analyses showed that inadequate quantities of microadditives result in losing the benefits coming from introduction of boron as the hardenability-improving element and can even result in a reduction of hardenability of the boron-containing steel.

Increase of resistance of piercing mill mandrels at seamless pipes production of 13Cr grade martensite class stainless steel at line ТПА 159‒426 of JSC VTZ

2020 ◽  
Vol 76 (12) ◽  
pp. 1259-1264
Author(s):  
I. I. Lube ◽  
N. V. Trutnev ◽  
S. V. Tumashev ◽  
A. V. Krasikov ◽  
A. G. Ul’yanov ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Oil And Gas ◽  
Cobalt Content ◽  
Pipe Plant ◽  
Piercing Mill ◽  
Steel Strength ◽  
New Material ◽  
Chemical Composition Of Steel ◽  
Technical Solutions ◽  
Grade Steel

At production of pipes of type 13Cr grade steel used at development of oil and gas deposits in areas with aggressive environment, intensive wear of instrument takes place, first of all, piercing mill mandrels. Factors, influencing the resistivity of the piercing mandrels considered, including chemical composition of the material, the mandrel is made of and its design. Based on industrial experience it was shown, that chrome content in the mandrel material practically does not affect on the increase of its resistivity, since the formed thin protective oxides having high melting temperature, are quickly failed and practically are not restored in the process of piercing. To increase the resistivity of piercing mandrels at production of casing tubes of type 13Cr grade steel, a work was accomplished to select a new material for their manufacturing. The chemical composition of steel presented, which was traditionally used for piercing mandrels manufacturing, as well as a steel grade proposed to increase their resistivity. First, molybdenum content was increased, which increases the characteristics of steel strength and ductility at high temperatures and results in grain refining. Second, tungsten content was also increased, which forms carbides in the steel resulting in an increase of its hardness and “red resistivity”, as well as in preventing grains growth during heating. Third, cobalt content was also increased, which increases heat resistivity and shock loads resistivity. The three elements increase enabled to increase the mandrels resistivity by two times. Results of mandrel test of steel 20ХН2МВ3КБ presented, the mandrel having corrugation on the working cone surface, which enabled to reach the resistivity growth to 12 passes without significant change of instrument cost. Microstructure of mandrels made of steels 20Х2Н4МФА and 20ХН2МВ3КБ shown. Application of the centering pin of special design was tested, which provided forming of a rounding edge on the front billet ends, eliminated undercut of mandrel external surface in the process of secondary billet grip and increase the service life of the piercing mill mandrels. At production of seamless pipes of martensite class type 13Cr stainless steels having L80 group of strength, an increase of piercing mandrel resistivity was reached by more than four times, which together with other technical solutions enabled to increase the hourly productivity of the hot rolling section of Volzhsky pipe plant ТПА 159-426 line by more than two times.

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