Polyesteramides Based on Linseed and Safflower Oils for Protective Coatings

2021 ◽  
pp. 89-99
Author(s):  
M. M. El-sawy ◽  
N. O. Shaker ◽  
E. M. Kandeel
Keyword(s):  
Protective Coatings ◽  
Impact Resistance ◽  
Steel Plates ◽  
Bending Test ◽  
Metal Alkoxide ◽  
Pencil Hardness ◽  
Bending Tests ◽  
Alkyd Resins ◽  
Flexible Films ◽  
Hardness Values

Polyesteramide resins were obtained and evaluated as vehicles and the variations of film performance in relation to the amide linkage were studied. Treatment of either linseed or safflower oils with diethanolamine with catalytic amounts of alkali metal alkoxide under relatively mild conditions led to a substantially complete conversion to N,N-(hydroxyethyl) linseed amide (HELA) and N,N-(hydroxyethyl) safflower amide (HESA). Polymerization of the polyols with diadipyl aromatic amines (aniline, p-toluidine, p-aminophenol and p-aminobenzoic acid) was carried out to yield polyesteramide derivatives having interesting surface coating properties. Such a substitution was claimed to give much harder, tougher, more flexible films with excellent chemical resistance in comparison with alkyd resins of similar oil length. The study includes stoving films mechanical evaluation as gloss percent at 60ºC, adhesion, impact, pencil hardness and bending tests using mild steel plates. The films also possess excellent impact resistance, high scratch hardness values, excellent bending test and good adhesion.

scholarly journals Impact resistance of steel materials to ballistic ejecta and shelter development using steel deck plates

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiroyuki Yamada ◽  
Kohei Tateyama ◽  
Shino Naruke ◽  
Hisashi Sasaki ◽  
Shinichi Torigata ◽  
...  
Keyword(s):  
Impact Energy ◽  
Impact Test ◽  
Impact Resistance ◽  
Protective Layer ◽  
High Strength ◽  
Steel Plates ◽  
Corrugated Plates ◽  
Shelter Construction ◽  
The Impact ◽  
Ballistic Ejecta

AbstractThe destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.

Effects of Delta - Ferrite Content on the Integrity of Reactor Vessel Cladding

2010 ◽  
Author(s):  
Ho-Sang Shin ◽  
Jin-Ki Hong ◽  
Koo-Kab Chung ◽  
Hae-Dong Chung ◽  
Gwang-Yil Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Reactor Vessel ◽  
Bending Test ◽  
Ferrite Content ◽  
Delta Ferrite ◽  
Bending Tests ◽  
Asme Code ◽  
Two Phases ◽  
Scanning Electron

As the design life of new nuclear power plant increases, the austenitic stainless cladding integrity of reactor vessel becomes one of the new concerns. Since 1970’s, there have been some specific recommendations on delta ferrite content of austenitic cladding of reactor vessels and welds. It has been known that the delta ferrite is beneficial for reducing micro-fissure in welds, though the high delta ferrite content increases the probability of embrittlment of welds. In this study, the mechanical and microstructural properties of austenitic weld metals with the limit values of the recommended range (5 ∼ 18 FN) of the delta ferrite control on low alloy steels were characterized by using bending test and scanning electron microscopy. The base metal was ASME Code Sec. II specification SA 508 Gr. 3 Cl. 1 plate and weld materials were EQ308L and EQ309L strips. Four kinds of cladding were deposited with submerged arc welding process on SA508 cl.3 plates. The bending tests were performed through ASME code Sec. IX and the microstructure of fractured surfaces was analyzed by scanning electron microscopy (SEM). In bending tests, there were no fractures except the highest delta ferrite content specimens (28FN). From the SEM observation of fractured surfaces, cracks initiated from the interface between austenite and ferrites phases in the cladding layer and propagated through the continuous interfaces between two phases. For specimens without continuous interfaces of two phases, though the cracks were observed in the interface of phases, the propagation of cracks was not observed. From the test results, continuous interfaces between austenite matrix and ferrite phase provide the path for crack propagation. And the delta ferrite content affects the integrity of cladding of reactor vessel.

Girth Weld Strength Matching Effect on Tensile Strain Capacity of Grade X70 High Strain Line Pipe

2018 ◽  
Author(s):  
Hisakazu Tajika ◽  
Takahiro Sakimoto ◽  
Tsunehisa Handa ◽  
Rinsei Ikeda ◽  
Joe Kondo
Keyword(s):  
High Strain ◽  
Limit State ◽  
Full Scale ◽  
Bending Test ◽  
High Grade ◽  
Line Pipe ◽  
Bending Tests ◽  
Strain Capacity ◽  
Pipeline Project ◽  
Pipe Bending

Recently high grade pipeline project have been planned in hostile environment like landslide in mountain area, liquefaction in reclaimed land or the frost heave in Polar Regions. Geohazards bring large scale ground deformation and effect on the varied pipeline to cause large deformation. Therefore, strain capacity is important for the pipeline and strain based design is also needed to keep gas transportation project in safe. High grade steel pipe for linepipe tends to have higher yield to tensile (Y/T) ratio and it has been investigated that the lower Y/T ratio of the material improves strain capacity in buckling and tensile limit state. In onshore pipeline project, pipe usually transported in 12 or 18m each and jointed in the field. Girth weld (GW) is indispensable so strength matching of girth weld towards pipe body is important. In this study strain capacity of Grade X70 high strain pipes with size of 36″ OD and 23mm WT was investigated with two types of experiments, which are full scale pipe bending tests and curved wide plate tests. The length of the specimen of full scale bending tests were approximately 8m and girth weld was made in the middle of joint length. A fixed internal pressure was applied during the bending test. Actual pipe situation in work was simulated and both circumferential and longitudinal stress occurred in this test. Test pipes were cut and welded, GTAW in first two layer and then finished by GMAW. In one pipe, YS-TS over-matching girth weld (OVM) joint was prepared considering the pipe body grade. For the other pipe, intentionally under-matching girth weld (UDM) joint was prepared. After the girth welding, elliptical EDM notch were installed in the GW HAZ as simulated weld defect. In both pipe bending tests, the buckling occurred in the pipe body at approximately 300mm apart from the GW and after that, deformation concentrated to buckling wrinkle. Test pipe breaking locations were different in the two tests. In OVM, tensile rupture occurred in pipe body on the backside of buckling wrinkle. In UDM, tensile rupture occurred from notch in the HAZ. In CWP test, breaking location was the HAZ notch. There were significant differences in CTOD growth in HAZ notch in these tests.

Long-Term Reliability Assessment of Bioceramics for Artificial Joints Using Microdamage Monitoring by AE

2006 ◽  
Vol 309-311 ◽  
pp. 1191-1194
Author(s):  
Shuichi Wakayama ◽  
Teppei Kawakami ◽  
Junji Ikeda
Keyword(s):  
Critical Stress ◽  
Reliability Assessment ◽  
Physiological Saline ◽  
Bending Test ◽  
Unstable Fracture ◽  
Artificial Joints ◽  
Bending Tests ◽  
Four Point Bending

Microfracture process during bending tests of alumina ceramics used for artificial joints was evaluated by acoustic emission (AE) technique. Four-point bending tests were carried out in air, refined water, physiological saline and simulated body fluid. AE behavior during bending test inhibited the rapid increasing point of AE events and energy prior to the final unstable fracture. It was understood that the bending stress at the increasing point corresponds to the critical stress for maincrack formation. The critical stress was affected by water in environments more strongly than fracture strength. Consequently, it was suggested that the characterization of maincrack formation is essential for the long-term reliability assessment of load-bearing bioceramics.

scholarly journals The Spread of Corrosion in Cast Iron and its Effect on the Life Cycle of Transportation Vehicles

2017 ◽  
Vol 65 (2) ◽  
pp. 383-389 ◽  
Author(s):  
Tomáš Binar ◽  
Jiří Švarc ◽  
Petr Dostál ◽  
Michal Šustr ◽  
Jan Tippner
Keyword(s):  
Impact Strength ◽  
Fractographic Analysis ◽  
Bending Test ◽  
Material Surface ◽  
Bending Tests ◽  
Corrosion Tests ◽  
Fracture Surfaces ◽  
Impact Bending ◽  
Notch Impact Strength ◽  
The Impact

This article deals with the spread of corrosion in material at different exposure times, and its effect on the measured brittle fracture and notch impact strength under different temperature conditions. To assess the degradational effect of corrosion on the material characteristics represented by the measured impact strength, we conducted a fractographic analysis of fracture surfaces, the aim of which was to evaluate the spread of corrosion in the material. In the first part of the experiment, two corrosion tests are simulated with a duration time of 432 and 648 hours, to compare the degradation effect of corrosion on the notch impact strength, depending on the duration of the corrosion tests. The following part shows the results of the impact bending test, where the experiment was conducted in an area of reduced and increased temperatures. The final part summarizes the results of the fractographic analysis of sample fracture surfaces from the impact bending tests. Based on the measured the length of the corrosion cracks, we analyzed the sample at the notch and from the material surface after the impact bending test.

scholarly journals Study of dependence between microstructure and chemical composition of A32, D32, E32 grades steels at bending tests

2019 ◽  
Vol 75 (1) ◽  
pp. 57-67
Author(s):  
L. A. Ryabicheva ◽  
R. E. Velikotskii
Keyword(s):  
Tensile Strength ◽  
Science Studies ◽  
Product Yield ◽  
Negative Influence ◽  
Mechanical Tests ◽  
Bending Test ◽  
Carbon Equivalent ◽  
Metal Science ◽  
Steel Rolling ◽  
Bending Tests

Meeting the high requirements to the whole complex of mechanical characteristics is the main criteria of reliability and long service life of shipbuilding steels. To determine them it is necessary to apply modern methodologies of metal science analysis. Revelation of regularity of influence of alloying, carbon equivalent, microstructure and production technology on results of bending test of low-alloyed grades А32, D32, Е32 shipbuilding steels was the purpose of the study. Production of steel, rolling, thermal treatment, mechanical tests and metal science studies of the low-alloyed shipbuilding steels was made in Alchevsk steel-works. A quantity estimation of the D32 grade sheets microstructure was made as a result of studies, having both satisfactory and not satisfactory results of bending tests. It was determined, that stitch oxides have the most negative influence on the results of bending tests for both hot-rolled and normalized sheets. Sheets with not satisfactory results of bending tests differ from those, which passed the tests by higher value of streakiness points, particular of perlite, and in normalized condition – by higher value of Widmanstatten pattern. Sheets, which did not passed the tests, have yield strength by 5–25 MPa and tensile strength by 14–39 MPa higher, while the tensile strength was by 1.2–4.8% lower. For stable yield in bending tests within 98–100% it is necessary the tensile strength level to be not less than 30%. It is reasonably all the sheets of 10–20 mm thick out of heats with carbon equivalent higher 0.54% to subject compulsory normalization. Further increase of the sheets product yield can be achieved by decreasing of phosphor mass share and increasing of general steel purity, first of all, by decreasing of oxide inclusions

Effect of Reduced Bond of Prestressed Strands

2016 ◽  
Vol 249 ◽  
pp. 296-300
Author(s):  
Jan L. Vítek ◽  
David Čítek
Keyword(s):  
Protective Coatings ◽  
Experimental Program ◽  
Winter Period ◽  
Bending Tests ◽  
Pull Out ◽  
Prestressing Strands ◽  
Post Tensioned

Bond of prestressing strands may be reduced by using protective coatings against corrosion during winter period, when early grouting of ducts may be impossible. It was not verified if the reduced bond has an influence on the performance of the post-tensioned structures. The experimental program was prepared, which investigated the bond of prestressing strands without protection and with two types of protective coatings. The program had two parts, laboratory pull-out tests and bending tests of large post-tensioned beams. The paper presents the results of this experimental program.

scholarly journals Performance of Flexible Chemoresistive Gas Sensors after Having Undergone Automated Bending Tests

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5190 ◽  
Author(s):  
Miriam Alvarado ◽  
Silvia De La Flor ◽  
Eduard Llobet ◽  
Alfonso Romero ◽  
José Luis Ramírez
Keyword(s):  
Metal Oxide ◽  
Gas Sensing ◽  
Flexible Substrate ◽  
Test Procedure ◽  
Chemical Vapor ◽  
Bending Test ◽  
Bending Tests ◽  
Ag Electrodes ◽  
Different Types ◽  
Before And After

Many sensors are developed over flexible substrates to be used as wearables, which does not guarantee that they will actually withstand being bent. This work evaluates the gas sensing performance of metal oxide devices of three different types, before and after having undergone automated, repetitive bending tests. These tests were aimed at demonstrating that the fabricated sensors were actually flexible, which cannot be taken for granted beforehand. The active layer in these sensors consisted of WO3 nanowires (NWs) grown directly over a Kapton foil by means of the aerosol-assisted chemical vapor deposition. Their response to different H2 concentrations was measured at first. Then, they were cyclically bent, and finally, their response to H2 was measured again. Sensors based on pristine WO3-NWs over Ag electrodes and on Pd-decorated NWs over Au electrodes maintained their performance after having been bent. Ag electrodes covered with Pd-decorated NWs became fragile and lost their usefulness. To summarize, two different types of truly flexible metal oxide gas sensor were fabricated, whereas a third one was not flexible, despite being grown over a flexible substrate following the same method. Finally, we recommend that one standard bending test procedure should be established to clearly determine the flexibility of a sensor considering its intended application.

Aspects of Testing and Material Properties of Fiber Concrete

2019 ◽  
Vol 292 ◽  
pp. 9-14 ◽  
Author(s):  
Oldrich Sucharda ◽  
Vlastimil Bilek
Keyword(s):  
Tensile Strength ◽  
Material Properties ◽  
Bending Test ◽  
Test Results ◽  
Functional Dependencies ◽  
Split Tensile Strength ◽  
Bending Tests ◽  
Fibre Concrete ◽  
Fiber Concrete ◽  
Concrete Mixer

Concrete is typical composite material and its properties can be very variable. Material properties are also influenced with the technology of processing, manufacturing and treatment after concreting. Reinforcement in form of fibers is often added for improving tensile strength. This paper deals with specific testing of fibre concrete. Test results of series of specimens are presented for selected transport concrete composition, which is reinforced with amount of fibers 25, 50, 75 kg / m3. Fibers were added directly into the into the concrete mixer in the factory. Each series includes more than 25 test samples. The tests include the compressive strength of a cube and cylindrical, testing of modulus of elasticity, and the split tensile strength in the direction perpendicular to and parallel to the filling. Within the research project also a few types of bending tests were performed. Four variants of bending test that vary in span of 500 or 600 mm, samples with and without a notch, and in a three- / four-point configuration. As a summary, broader evaluation and functional dependencies are derived.

scholarly journals Screw head plugs increase the fatigue strength of stainless steel, but not of titanium, locking plates

2018 ◽  
Vol 7 (12) ◽  
pp. 629-635 ◽  
Author(s):  
L-W. Hung ◽  
C-K. Chao ◽  
J-R. Huang ◽  
J. Lin
Keyword(s):  
Stainless Steel ◽  
Fatigue Strength ◽  
Steel Plates ◽  
Bending Test ◽  
Type I ◽  
Locking Plates ◽  
Type Ii ◽  
Screw Head ◽  
Type Iii ◽  
Four Point Bending

ObjectivesScrew plugs have been reported to increase the fatigue strength of stainless steel locking plates. The objective of this study was to examine and compare this effect between stainless steel and titanium locking plates.MethodsCustom-designed locking plates with identical structures were fabricated from stainless steel and a titanium alloy. Three types of plates were compared: type I unplugged plates; type II plugged plates with a 4 Nm torque; and type III plugged plates with a 12 Nm torque. The stiffness, yield strength, and fatigue strength of the plates were investigated through a four-point bending test. Failure analyses were performed subsequently.ResultsFor stainless steel, type II and type III plates had significantly higher fatigue strength than type I plates. For titanium, there were no significant differences between the fatigue strengths of the three types of plates. Failure analyses showed local plastic deformations at the threads of screw plugs in type II and type III stainless steel plates but not in titanium plates.ConclusionThe screw plugs could increase the fatigue strength of stainless steel plates but not of titanium plates. Therefore, leaving screw holes open around fracture sites is recommended in titanium plates. Cite this article: L-W. Hung, C-K. Chao, J-R. Huang, J. Lin. Screw head plugs increase the fatigue strength of stainless steel, but not of titanium, locking plates. Bone Joint Res 2018;7:629–635. DOI: 10.1302/2046-3758.712.BJR-2018-0083.R1.

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