scholarly journals Butt welding of thin sheets of S960MC steel

2021 ◽  
Vol 93 (2) ◽  
pp. 5-12
Author(s):  
Miloš Mičian ◽  
Martin Frátrik ◽  
Libor Trško ◽  
Marek Gucwa ◽  
Jerzy Winczek ◽  
...  

The paper presents the application of MAG welding to TMCP steels (thermo-mechanically controlled processed) grade S960MC and 3 mm thick. In the analyzed joints, the research focused on their mechanical properties and changes in the heat-affected zone (HAZ) that occur in this type of steels. The hardness and tensile strength tests carried out showed a significant decrease in the properties of the joint compared to the declared values of the base material and the filler material used in the tests. In the case of hardness, it was a decrease of 34% in HAZ and by 15-21% in relation to the strength limit. Changes in HAZ properties of a joint correlate with changes in its structure.

2019 ◽  
Vol 5 (2) ◽  
pp. 36-40
Author(s):  
Sunardi Klaten

Steel plate making can be produced by hot and cold rolling method. To obtain the optimal results, the production on the cold rolling mill (CRM) must be carried out continuously. This CRM is equipped with a flash butt welding machine to connect between one plate and anothers. The purpose of this research is to determine the effect of thickness reduction on mechanical properties of steel JIS 3141. The method used in this study is experimental, namely mechanical properties testing at weld area, heat affected zone (HAZ) and base material. The thickness reductions used in this research are 0%, 69,78%, 71,56% and 73,33%. The material characteristics observed were hardness, tensile strength, yield strength, elaongation and corrosion rate. From this study it is known that the thickness reduction 73.33% resulted the best mechanical properties. The values ​​of hardness, tensile strength, yield strength and corrosion rate were 82.26 HRB, 644 N / mm2, 501 N / mm2 and 1.3844 mpy, respectively.


2018 ◽  
Vol 36 (6) ◽  
pp. 1609-1628 ◽  
Author(s):  
Chengzheng Cai ◽  
Feng Gao ◽  
Yugui Yang

Liquid nitrogen is a type of super-cryogenic fluid, which can cause the reservoir temperature to decrease significantly and thereby induce formation rock damage and cracking when it is injected into the wellbore as fracturing fluid. An experimental set-up was designed to monitor the acoustic emission signals of coal during its contact with cryogenic liquid nitrogen. Ultrasonic and tensile strength tests were then performed to investigate the effect of liquid nitrogen cooling on coal cracking and the changes in mechanical properties thereof. The results showed that acoustic emission phenomena occurred immediately as the coal sample came into contact with liquid nitrogen. This indicated that evident damage and cracking were induced by liquid nitrogen cooling. During liquid nitrogen injection, the ring-down count rate was high, and the cumulative ring-down counts also increased rapidly. Both the ring-down count rate and the cumulative ring-down counts during liquid nitrogen injection were much greater than those in the post-injection period. Liquid nitrogen cooling caused the micro-fissures inside the coal to expand, leading to a decrease in wave velocity and the deterioration in mechanical strength. The wave velocity, which was measured as soon as the sample was removed from the liquid nitrogen (i.e. the wave velocity was recorded in the cooling state), decreased by 14.46% on average. As the cryogenic samples recovered to room temperature, this value increased to 18.69%. In tensile strength tests, the tensile strengths of samples in cooling and cool-treated states were (on average) 17.39 and 31.43% less than those in initial state. These indicated that both during the cooling and heating processes, damage and cracking were generated within these coal samples, resulting in the acoustic emission phenomenon as well as the decrease in wave velocity and tensile strength.


2012 ◽  
Vol 17 (6) ◽  
pp. 154-159 ◽  
Author(s):  
Marcel M. Farret ◽  
Eduardo Martinelli de Lima ◽  
Eduardo Gonçalves Mota ◽  
Hugo Mitsuo S. Oshima ◽  
Gabriela Maguilnik ◽  
...  

OBJECTIVE: To evaluate the mechanical properties of three glass ionomers cements (GICs) used for band cementation in Orthodontics. METHODS: Two conventional glass ionomers (Ketac Cem Easy mix/3M-ESPE and Meron/Voco) and one resin modified glass ionomer (Multi-cure Glass ionomer/3M-Unitek) were selected. For the compressive strength and diametral tensile strength tests, 12 specimens were made of each material. For the microhardness test 15 specimens were made of each material and for the shear bond strength tests 45 bovine permanent incisors were used mounted in a self-cure acrylic resin. Then, band segments with a welded bracket were cemented on the buccal surface of the crowns. For the mechanical tests of compressive and diametral tensile strength and shear bond strength a universal testing machine was used with a crosshead speed of 1,0 mm/min and for the Vickers microhardness analysis tests a Microdurometer was used with 200 g of load during 15 seconds. The results were submitted to statistical analysis through ANOVA complemented by Tukey's test at a significance level of 5%. RESULTS: The results shown that the Multi-Cure Glass Ionomer presented higher diametral tensile strength (p < 0.01) and compressive strength greater than conventional GICs (p = 0.08). Moreover, Ketac Cem showed significant less microhardness (p < 0.01). CONCLUSION: The resin-modified glass ionomer cement showed high mechanical properties, compared to the conventional glass ionomer cements, which had few differences between them.


Author(s):  
Martin Hukle ◽  
Brian Newbury ◽  
Dan Lillig ◽  
Jonathan Regina ◽  
Agnes Marie Horn

The intelligent design of a given pipeline system intended for operation beyond the elastic limit should incorporate specific features into both the base material (line pipe) and girth weld that enable the affected system to deform safely into the plastic regime within the intended strain demand limits. The current paper focuses on the mechanical properties known to influence the strain capacity of the base material (i.e., line pipe steel independent of the girth weld). Line pipe mechanical properties of interest include: longitudinal yield strength, tensile strength, yield to tensile strength ratio, reduction of area, elongation and uniform elongation. Of particular interest (in consideration of the conventional thermally applied corrosion protection coating systems to be employed), are the longitudinal mechanical properties in the “aged” condition. The present study investigates six (6) different pipeline steels encompassing grades X60 (415 MPa) to X100 (690 MPa), and includes both UOE Submerged Arc Welded - Longitudinal (SAW-L) and seamless (SMLS) forming methods.


2009 ◽  
Vol 410-411 ◽  
pp. 87-96 ◽  
Author(s):  
Markku Keskitalo ◽  
Kari Mäntyjärvi

The laser weldability of austenitic stainless steel (ASS) is good because of the material’s high absorptivity and favourable microstructure. There can be a slight possibility of solidification cracking at high welding speeds and low Crekv/Niekv ratios. Test welds were welded with a Yb:YAG disc laser. The test material was 3.2 mm EN 1.4404 2H C700 type stainless steel plate which was work hardened by cold rolling. The test materials were welded with different heat inputs ranging from 0.024 kJ/mm to 0.12 kJ/mm and with 300 mm and 200 mm focal lengths. The weld seams were square-groove welded as butt weld without filler material. The edges of the groove were made by mechanical or laser cutting. The hardness profiles from cross-sections of the welds were measured with a Vickers microhardness tester using 200 g weight. The mechanical properties were tested with tensile tests. The welds were classified with radiographic verification by an accredited laboratory. A number of the welds were fatigue tested with a bending fatigue tester. The mechanical properties (Rp 0.2%, Rm) of the laser welds were almost the same as in the base material except at the highest heat input. In the radiographic classification, the welds which were welded to the laser-cut edge were classified as class B (accepted). The other welds were classified as class D or C (rejected). The main reasons for the rejection of welds made on mechanically cut edges were lack of penetration or undercut of the weld. A problem with mechanically cut edges, and hence the welds, is that they can be non-square and bent edge. Fatigue tests and tensile tests gave no evidence of solidification cracking in the microstructure of the solidified parts of the welds.


2019 ◽  
Vol 19 (11) ◽  
pp. 7476-7486
Author(s):  
Jinze Du ◽  
Hongyan Zeng ◽  
Enguo Zhou ◽  
Bo Feng ◽  
Chaorong Chen ◽  
...  

The microcapsule nanoparticles were prepared by in-situ copolymerization of hydrotalcites (MAH) with the polymer (MF, PF, PS and PU) monomers, respectively, where the MF-wrapped MAH (MAH@MF) had the best monodispersity. The composites of the microcapsules and EVA were prepared by incorporating the microcapsule nanoparticles into ethylene vinyl acetate (EVA), respectively. To further understand the intrinsic correlation between microcapsule fillers and EVA matrix, molecular dynamics (MD) simulation was introduced to qualitatively analyze the contribution of microcapsule fillers on improving compatibility and mechanical properties of the EVA matrix. The compatibility of microcapsule nanoparticles with EVA matrix were detected in sequence through SEM, DSC and tensile strength tests. And the combustion, thermal behavior and flame retardance were also characterized by TG analyses as well as LOI and UL-94 level. As a result, the MAH@MF filler had the best performances in improving the flame retardancy and mechanical properties among the microcapsule fillers, attributed to high compatibility of the MAH@MF and EVA matrix, which made uniform distribution of the MAH@MF filler due to the reciprocity of triazine functional ring with vinyl acetate linkages.


2017 ◽  
Vol 754 ◽  
pp. 383-386
Author(s):  
Kee Nam Song

Different microstructures in the weld zone of a metal structure including a fusion zone and a heat affected zone, are formed as compared to the base material. Consequently, the mechanical properties in the weld zone are different from those in the base material to a certain degree owing to different microstructures and residual welding stresses. When a welded structure is loaded, the mechanical behavior of the welded structure might be different from the case of a structure with homogeneous mechanical properties. It is known that obtaining the mechanical properties in the weld is generally difficult owing to the narrow regions of the weld and interfaces. As an alternative way to obtain the weld mechanical properties, the weld mechanical properties of Alloy800HT, SUS316L, and Alloy617, were recently measured using an instrumented indentation technique, and the representative weld mechanical properties of these materials were estimated with a 95% lower confidence level for later structural analyses of the welded structures.


Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1536
Author(s):  
Jaewoong Kim ◽  
Jisun Kim ◽  
Changmin Pyo

As the environmental regulations on ship emissions by the International Maritime Organization (IMO) become stricter, the demand for a ship powered by liquefied natural gas (LNG) is rapidly increasing worldwide. Compared to other materials, high-manganese steel has the advantages of superior impact toughness at cryogenic temperatures, a low thermal expansion coefficient, and a low-cost base material and welding rod. However, there is a limitation that the mechanical properties of a filler material are worse than those of a base material that has excellent mechanical properties. To solve these shortcomings, a basic study was performed to apply fiber laser welding with little welding deformation and no filler material to high-manganese steel. The relationship between laser welding parameters and penetration shapes was confirmed through cross-section observation and analysis by performing a bead on plate (BOP) test by changing laser power and welding speed, which are the main parameters of laser welding. In addition, the welding performance was evaluated through mechanical property tests (yield strength, tensile strength, hardness, cryogenic impact strength) of a welding part after performing the high-manganese steel laser butt welding experiment. As a result, it was confirmed that the yield strength of a high-manganese steel laser welding part was 97.5% of that of a base metal, and its tensile strength was 93.5% of that of a base metal.


2013 ◽  
Vol 811 ◽  
pp. 146-151
Author(s):  
Chen Wei Chen ◽  
Fu Xin Yang ◽  
Li Xin Lu ◽  
Jin Xie ◽  
Li Li

The Flexible Intermediate Bulk Container (FIBC) is a flexible transportation packaging container that is weaved by polyolefin plastic ribbon-like filament, which is widely used in the storage and transportation of granular and powder materials. When the FIBC was affected by environment factors synthetically under using, such as light, heat and air etc, it would come into degradation and its mechanical properties reduced. In this study, the basic mechanical properties of polypropylene FIBC base material were tested by tensile experiment and the reason of main base material mechanical properties difference between theoretical value and experimental value was analyzed. Based on the FIBC different using environments, the natural exposure experiment and high/low temperature experiments were carried out, we took tensile strength holding ratio and elongation holding ratio as evaluating indicator and analyzed law of influence of the different experiment condition on base material mechanical properties, which provided valuable reference for FIBC designing and manufacturing. Along with the experiment time increased, the color of base material changed from milk white to yellow slowly, the tensile strength and elongation reduced, the influencing grade was as follow: natural exposure>high temperature>low temperature. The results of natural exposure experiment showed that there was difference of anti-aging performance among the FIBC base material, the mechanical properties of woof fabric and belt reduced evidently, while others reduced slowly. For high (45°C)/low (-25°C) temperature experiments, the reduction of FIBC base materials mechanical properties were not obvious and woof fabric reduced a little faster comparatively.


2013 ◽  
Vol 535-536 ◽  
pp. 215-218 ◽  
Author(s):  
Bin Wang ◽  
X. Chao ◽  
Y. Li ◽  
S.R. Reid

Electrospinning technology was used to obtain non-woven sheets made from fine fibres in a controllable diameter range from 50 nm to 3 µm. Poly(ethylene-co-vinyl alcohol), a large molecule polymer was chosen to make the fibres for its biodegradable and biocompatible properties. The thin sheets obtained were tested in uniaxial tension for their mechanical properties in view of the potential use as wound dressings. It is found that the sheets show a mild hardening behavior with extensive elongation and necking before failure in multiple fractures at random locations. Due to the random orientation of the continuous fibres in the sheet, detachment, shear, straightening and twinning. etc., occur amongst fibres to different extends at the same time. The Young’s modulus and the yield stress (at 0.4~0.5% proof strains) are predominately affected by fibre diameters, and are largely insensitive to strain rate over the range tested.


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