scholarly journals Mechanical Properties of Cast-in Anchor Bolts Manufactured of Reinforcing Tempcore Steel

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2075
Author(s):  
Bahleda ◽  
Bujňáková ◽  
Koteš ◽  
Hasajová ◽  
Nový
Keyword(s):  
Mechanical Properties ◽  
Base Material ◽  
High Strength ◽  
Correlation Relationship ◽  
Rolling Mills ◽  
Hardness Tests ◽  
Anchor Bolts ◽  
Tempcore Process ◽  
Non Destructive ◽  
Recommendations For Assessment

The tempcore process is implemented in rolling mills to produce high strength reinforcing steel. Besides being used as reinforcement, rebars are also used as the base material for the manufacturing of anchor bolts. The mechanical properties of reinforcement bars used in Europe are assessed in accordance with Eurocode without the recommendations for cast-in anchor bolts. The material properties of Tempcore rebars are not homogenous over the bar cross section. The European Assessment Document (EAD) for the cast-in anchor bolts does not exactly specify the mechanical properties of the thread part. The aim of these experiments is to show the different mechanical properties of rebars and their thread parts. The experiments were performed on rebars modified by peeling to characterize the reduction of diameter in a thread part. As a possible way to predict mechanical properties in a non-destructive way, the hardness tests were performed. Next, the application of the correlation relationship between hardness and tensile strength has been determined. The paper formulates preliminary recommendations for assessment of the cast-in anchor bolts in practice.

scholarly journals A Study on Rotary Friction Welding of Titanium Alloy (Ti6Al4V)

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ho Thi My Nu ◽  
Truyen The Le ◽  
Luu Phuong Minh ◽  
Nguyen Huu Loc
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
Friction Welding ◽  
Base Material ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Experimental Results ◽  
Thermomechanical Model ◽  
Rotary Friction Welding

The selection of high-strength titanium alloys has an important role in increasing the performance of aerospace structures. Fabricated structures have a specific role in reducing the cost of these structures. However, conventional fusion welding of high-strength titanium alloys is generally conducive to poor mechanical properties. Friction welding is a potential method for intensifying the mechanical properties of suitable geometry components. In this paper, the rotary friction welding (RFW) method is used to study the feasibility of producing similar metal joints of high-strength titanium alloys. To predict the upset and temperature and identify the safe and suitable range of parameters, a thermomechanical model was developed. The upset predicted by the finite element simulations was compared with the upset obtained by the experimental results. The numerical results are consistent with the experimental results. Particularly, high upset rates due to generated power density and forging pressure overload that occurred during the welding process were investigated. The performances of the welded joints are evaluated by conducting microstructure studies and Vickers hardness at the joints. The titanium rotary friction welds achieve a higher tensile strength than the base material.

scholarly journals The influence of welding heat input on the quality and properties of high strength low-alloy dissimilar steel butt joints

2020 ◽  
Vol 92 (2) ◽  
pp. 15-23
Author(s):  
Jacek Tomków ◽  
Jacek Haras
Keyword(s):  
Mechanical Properties ◽  
Heat Input ◽  
High Strength ◽  
Bending Test ◽  
Carbon Equivalent ◽  
Butt Joints ◽  
Dissimilar Steel ◽  
Static Tensile ◽  
Steel Joints ◽  
Non Destructive

The paper presents the results of non-destructive and destructive tests od dissimilar high-strength low-alloy S460ML and S460N butt joints. These steels are characterized by similar mechanical properties, but their carbon equivalent CeIIW is much different. The joints were made using different values of heat input for each welding bead. They were tested by non-destructive methods: visual, penetrant, radiographic and ultrasonic tests. Then, the destructive tests were made: static tensile test, bending test, impact test and Vickers HV10 hardness measurements. The results of prepared examinations showed, that welding with higher heat input has significant impact on the mechanical properties of the dissimilar steel joints – the joint welded with bigger heat input was characterized by better mechanical properties.

Development of Ti-MMCs by the Use of Different Reinforcements via Conventional Hot-Pressing

2016 ◽  
Vol 704 ◽  
pp. 400-405 ◽  
Author(s):  
Cristina Arévalo ◽  
Michael Kitzmantel ◽  
Erich Neubauer ◽  
Isabel Montealegre-Meléndez
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
Metal Matrix ◽  
High Strength ◽  
Strengthening Effect ◽  
Light Weight ◽  
Matrix Composites ◽  
Amorphous Boron ◽  
Hardness Tests ◽  
History Of

Titanium and its alloys have evolved faster than any structural material in the history of metallurgy. The increasing employment of titanium in many different applications is mainly due to its light weight, high strength and structural efficiency. The titanium metal matrix composites (Ti-MMCs) have helped to achieve these objectives. The aim of this work is the development and study of Ti-MMCs manufactured via hot pressing at 900 °C reinforced by sub-micron and micron boron carbide (B4C), amorphous boron and sub-micron and micron titanium diboride (TiB2) particles in order to improve its mechanical properties. Full dense composites were obtained with this consolidation technique. The influence of the different reinforcements has been analyzed. Moreover, the strengthening effect of sub-micron reinforcements is compared to the effect of the material with the same chemical composition in a micro-scaled phase. Comparison has been established studying the microstructure (grain size and density) and mechanical properties through tensile and hardness tests.

scholarly journals The Precipitation Processes and Mechanical Properties of Aged Inconel 718 Alloy After Annealing

2017 ◽  
Vol 62 (3) ◽  
pp. 1695-1702 ◽  
Author(s):  
P. Maj ◽  
B. Adamczyk-Cieslak ◽  
M. Slesik ◽  
J. Mizera ◽  
T. Pieja ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Inconel 718 ◽  
Aging Process ◽  
High Strength ◽  
Inconel 718 Alloy ◽  
Transmission Microscopy ◽  
Nickel Iron ◽  
Temperature Range ◽  
Hardness Tests ◽  
Strength And Ductility

AbstractInconel 718 is a precipitation hardenable nickel-iron based superalloy. It has exceptionally high strength and ductility compared to other metallic materials. This is due to intense precipitation of the γ’ and γ” strengthening phases in the temperature range 650-850°C. The main purpose of the authors was to analyze the aging process in Inconel 718 obtained in accordance with AMS 5596, and its effect on the mechanical properties. Tensile and hardness tests were used to evaluate the mechanical properties, in the initial aging process and after reheating, as a function of temperature and time respectively in the ranges 650°-900°C and 5-480 min. In addition, to link the mechanical properties with the microstructure transmission microscopy observations were carried out in selected specimens. As a result, factors influencing the microstructure changes at various stages of strengthening were observed. The authors found that the γ’’ phase nucleates mostly homogenously in the temperature range 650-750°C, causing the greatest increase in strength. On the other hand, the γ’ and δ phases are formed heterogeneously at 850°C or after longer annealing in 800°C, which may weaken the material.

scholarly journals The Analysis of the Post-Operation Microstructure and Mechanical Properties of the Similar Welded Joint

2020 ◽  
pp. 37-41
Author(s):  
Agata Merda ◽  
Klaudia Klimaszewska
Keyword(s):  
Mechanical Properties ◽  
Welded Joint ◽  
Base Material ◽  
Steam Pressure ◽  
Test Material ◽  
Quality Level ◽  
Fine Grained ◽  
Post Operation ◽  
Non Destructive ◽  
M23c6 Carbides

The test material was a specimen sampled from sections of a pipe operated for 41,914 hours at a temperature of 575°C and under a steam pressure of 28.2 MPa. The specimen subjected to metallurgical tests was a welded joint made of austenitic steel TP347HFG. The non-destructive tests and the macroscopic tests confirmed the lack of any welding imperfections. The test joint represented quality level B in accordance with related standard requirements. The microstructural tests of the heat-affected zone (HAZ) revealed the presence of the fine-grained austenitic structure with numerous precipitates on grain boundaries – probably M23C6 carbides. In spite of long-lasting operation, the mechanical properties of the test welded joint were high and did not exceed the standard-related requirements concerning the base material.

Influence of Friction Stir Welding Parameters on the Mechanical Properties of EN AW-7075 Weld Joints

2016 ◽  
Vol 835 ◽  
pp. 210-215
Author(s):  
Máté Nagy ◽  
Mária Behúlová
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Ultimate Strength ◽  
Base Material ◽  
High Strength ◽  
Welding Parameters ◽  
Micro Hardness ◽  
Friction Stir ◽  
Weld Joints ◽  
Welding Processes

The paper deals with the friction stir welding (FSW) of the high strength EN AW 7075-T651 aluminium alloy with the aim to analyze the influence of welding parameters on the mechanical properties of Al-weld joints. FSW represents relatively novel solid-state technology of material joining which can be successfully applied for welding of several metallic alloys including the high-strength aluminium alloys that are hard to weld by conventional fusion welding processes. In cooperation with VÚZ - PI SR Bratislava, nine experimental weld joints of samples with dimensions of 300 × 150 × 10 mm were prepared using the welding machine of the FSW-LM-060 type and different parameters of welding – the welding speed from 60 to 120 mm/min and the tool rotation rate from 600 to 1000 rpm in clockwise direction. The quality of weld joints was evaluated by static tensile tests and micro-hardness measurements. According to obtained results of tensile testing, the average values of ultimate strength of weld joints are by 32.2 % lower comparing with the ultimate strength of the base material. On the other hand, the ductility increased by 7.2 %. The highest micro-hardness of weld joints at the level of 129 HV was measured in thermo-mechanically affected zone on the retreating side.

Mechanical properties of Fe-based bulk glassy alloys in Fe–B–Si–Nb and Fe–Ga–P–C–B–Si systems

2003 ◽  
Vol 18 (6) ◽  
pp. 1487-1492 ◽  
Author(s):  
A. Inoue ◽  
B. L. Shen ◽  
A. R. Yavari ◽  
A. L. Greer
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Vickers Hardness ◽  
Glassy Alloy ◽  
High Strength ◽  
Deformation Mode ◽  
Soft Magnetic Materials ◽  
Elastic Plastic ◽  
Glassy Alloys ◽  
Hardness Tests

Mechanical properties of cast Fe-based bulk glassy alloy rods with compositions of (Fe0.75B0.15Si0.1)96Nb4 and Fe77Ga3P9.5C4B4Si2.5 were examined by compression and Vickers hardness tests. The Young's modulus (E), yield strength (σy), fracture strength (σf), elastic strain (εe), fracture strain (εf), and Vickers hardness (Hv) were 175 GPa, 3165 MPa, 3250 MPa, 1.8%, 2.2%, and 1060, respectively, for the former alloy and 182 GPa, 2980 MPa, 3160 MPa, 1.9%, 2.2%, and 870, respectively, for the latter alloy. The εf /E and Hv/3E were 0.019–0.017 and 0.020–0.016, respectively, for the alloys, in agreement with the previous data for a number of bulk glassy alloys. The agreement suggests that these Fe-based bulk glassy alloys have an elastic–plastic deformation mode. The syntheses of high-strength Fe-based bulk glassy alloys with distinct compressive plastic strain and elastic–plastic deformation mode are encouraging for future development of Fe-based bulk glassy alloys as structural and soft magnetic materials.

scholarly journals Structural Aspects of Execution and Thermal Treatment of Welded Joints of Hardox Extreme Steel

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 915 ◽  
Author(s):  
Konat
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Welded Joints ◽  
Base Material ◽  
Steel Structures ◽  
High Strength ◽  
Carbon Equivalent ◽  
Material Structure ◽  
Welding Processes ◽  
Structural Aspects

The paper presents structure and mechanical properties of welded joints of the high-strength, abrasive-wear resistant steel Hardox Extreme. It was shown that, as a result of welding this steel, structures conducive to lowering its abrasion-wear resistance are created in the heat-affected zone. Width of the zone exceeds 60 mm, which results in accelerated wear in the planned applications. On the grounds of the carried-out examinations of structures and selected mechanical properties, a welding technology followed by heat treatment of heat-affected zones was suggested, leading to reconstruction of HAZ structures that is morphologically close to the base material structure. In spite of high carbon equivalent (CEV) of Hardox Extreme, the executed welding processes and heat treatment did not result in the appearance, in laboratory conditions, of welding imperfections in the welded joints.

scholarly journals Microstructure and Mechanical Properties of Laser-Welded DP Steels Used in the Automotive Industry

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 456
Author(s):  
Hanbing He ◽  
Farnoosh Forouzan ◽  
Joerg Volpp ◽  
Stephanie M. Robertson ◽  
Esa Vuorinen
Keyword(s):  
Mechanical Properties ◽  
Fatigue Limit ◽  
Welded Joints ◽  
Base Material ◽  
High Strength ◽  
Strength Properties ◽  
Fatigue Tests ◽  
Steel Sheets ◽  
Lower Elongation ◽  
Similar Yield

The aim of this work was to investigate the microstructure and the mechanical properties of laser-welded joints combined of Dual Phase DP800 and DP1000 high strength thin steel sheets. Microstructural and hardness measurements as well as tensile and fatigue tests have been carried out. The welded joints (WJ) comprised of similar/dissimilar steels with similar/dissimilar thickness were consisted of different zones and exhibited similar microstructural characteristics. The trend of microhardness for all WJs was consistent, characterized by the highest value at hardening zone (HZ) and lowest at softening zone (SZ). The degree of softening was 20 and 8% for the DP1000 and DP800 WJ, respectively, and the size of SZ was wider in the WJ combinations of DP1000 than DP800. The tensile test fractures were located at the base material (BM) for all DP800 weldments, while the fractures occurred at the fusion zone (FZ) for the weldments with DP1000 and those with dissimilar sheet thicknesses. The DP800-DP1000 weldment presented similar yield strength (YS, 747 MPa) and ultimate tensile strength (UTS, 858 MPa) values but lower elongation (EI, 5.1%) in comparison with the DP800-DP800 weldment (YS 701 MPa, UTS 868 MPa, EI 7.9%), which showed similar strength properties as the BM of DP800. However, the EI of DP1000-DP1000 weldment was 1.9%, much lower in comparison with the BM of DP1000. The DP800-DP1000 weldment with dissimilar thicknesses showed the highest YS (955 MPa) and UTS (1075 MPa) values compared with the other weldments, but with the lowest EI (1.2%). The fatigue fractures occurred at the WJ for all types of weldments. The DP800-DP800 weldment had the highest fatigue limit (348 MPa) and DP800-DP1000 with dissimilar thicknesses had the lowest fatigue limit (<200 MPa). The fatigue crack initiated from the weld surface.

scholarly journals Wire Arc Additive Manufacturing with Novel Al-Mg-Si Filler Wire—Assessment of Weld Quality and Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1243
Author(s):  
René Winterkorn ◽  
Andreas Pittner ◽  
Michael Rethmeier
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Treatment Strategies ◽  
Base Material ◽  
High Strength ◽  
Solidification Cracking ◽  
Filler Wire ◽  
Equiaxed Grains ◽  
Wire Arc Additive Manufacturing

Wire arc additive manufacturing enables the production of near-net shape large-volume metallic components leveraging an established industrial base of welding and cladding technology and adapting it for layer-wise material deposition. However, the complex relationship between the process parameters and resulting mechanical properties of the components still remains challenging. In case of high-strength Al-Mg-Si aluminum alloys, no commercial filler wires are yet available due the high susceptibility of solidification cracking as well as the necessary efforts to obtain acceptable mechanical properties. To address this need, we evaluated a novel filler wire based on AlMg0.7Si doped with a Ti5B1 master alloy to foster fine equiaxed grains within the deposited metal. The correlation between the process parameters and component quality was examined by analyzing the size and distribution of pores as well as the grain morphology. Furthermore, we evaluated the influence of different post-weld heat treatment strategies to achieve mechanical properties corresponding to the reference wrought material. We demonstrated that fine equiaxed grains in the weld metal reduced the susceptibility of solidification cracking significantly. The novel AlMg0.7Si-TiB (S Al 6063-TiB) filler wire facilitated wire arc additive manufacturing of high-strength aluminum components with mechanical properties that were almost as superior as the corresponding wrought base material.

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