Experimental Study of Stress Corrosion of High-Strength Wires Affected by Four Typical Ions

2012 ◽  
Vol 226-228 ◽  
pp. 1597-1603 ◽  
Author(s):  
Jian Guo Yin ◽  
Chu Han Deng ◽  
Yu Guang Fu ◽  
Liu Chi Li

Characterized by light weight and high strength, cold-drawn galvanized cable wires are widely applied in all kinds of prestressed structures and cable structures. Investigation shows that cables are sensitive to corrosion. Severe corrosion of cables results in cable replacement which are costly, and even more, collapse of the whole bridge. In this paper, several tests were carried out to present the crack growth of wire in stress corrosion in different solutions. In particular, as Cl-, OH-, SO42- and NH4+ have major effect on stress corrosion in seawater and acid rain, these four kinds of ions are selected in tests. And all four kinds of corrosive solutions are tested with the concentration of 1.5 bsp and 3 bsp respectively. Effects on ultimate tensile strength and sensitivity of cable wires are different for each of chosen ions, and the increasing concentration for the same solution would drop ultimate tensile strength and the modulus of cable wires.

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 647 ◽  
Author(s):  
Bingrong Zhang ◽  
Lingkun Zhang ◽  
Zhiming Wang ◽  
Anjiang Gao

In order to obtain high-strength and high-ductility Al–Si–Cu–Mg alloys, the present research is focused on optimizing the composition of soluble phases, the structure and morphology of insoluble phases, and artificial ageing processes. The results show that the best matches, 0.4 wt% Mg and 1.2 wt% Cu in the Al–9Si alloy, avoided the toxic effect of the blocky Al2Cu on the mechanical properties of the alloy. The addition of 0.6 wt% Zn modified the morphology of eutectic Si from coarse particles to fine fibrous particles and the texture of Fe-rich phases from acicular β-Fe to blocky π-Fe in the Al–9Si–1.2Cu–0.4Mg-based alloy. With the optimization of the heat treatment parameters, the spherical eutectic Si and the fully fused β-Fe dramatically improved the ultimate tensile strength and elongation to fracture. Compared with the Al–9Si–1.2Cu–0.4Mg-based alloy, the 0.6 wt% Zn modified alloy not only increased the ultimate tensile strength and elongation to fracture of peak ageing but also reduced the time of peak ageing. The following improved combination of higher tensile strength and higher elongation was achieved for 0.6 wt% Zn modified alloy by double-stage ageing: 100 °C × 3 h + 180 °C × 7 h, with mechanical properties of ultimate tensile strength (UTS) of ~371 MPa, yield strength (YS) of ~291 MPa, and elongation to fracture (E%) of ~5.6%.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1511 ◽  
Author(s):  
Nannan Zhao ◽  
Chunyan Ban ◽  
Hongfei Wang ◽  
Jianzhong Cui

The mechanical properties and electrical conductivity of 6063 aluminum alloy subjected to equal-channel angular press (ECAP) at room temperature (RT), 200 °C, and two-step temperature schedule (TST) have been investigated in this study. The TST refers to one pass at 200 °C followed by further successive pressing at RT. It is shown that this method is effective in obtaining the combination of high strength and electrical conductivity. After two passes, the higher strength can be achieved in TST condition (328 MPa yield strength and 331 MPa ultimate tensile strength), where the changing parameter is processing temperature from the first pass at 200 °C to the second pass at RT, as compared to two passes in RT condition (241 MPa yield strength and 250 MPa ultimate tensile strength) and two passes in 200 °C condition (239 MPa yield strength and 258 MPa ultimate tensile strength). This performance could be associated with grain refinement and nanosized precipitates in TST condition. Moreover, in contrast to RT condition, a higher electrical conductivity was observed in TST condition. It reveals that high strength and electrical conductivity of 6063 aluminum alloy can be obtained simultaneously by ECAP processing in TST condition because of ultrafine-grained microstructure and nanosized precipitates.


2012 ◽  
Vol 184-185 ◽  
pp. 940-943
Author(s):  
Wei Lv ◽  
Di Wu ◽  
Zhuang Li

In the present paper, controlled cooling in different ways was performed using a laboratory hot rolling mill in ultra-high strength hot rolled ferrite-bainite dual phase (DP) steel. The results have shown that the final microstructures of DP steel comprise ferrite, bainite and a small amount of retained austenite and martensite. DP steel has a tensile strength ranging from 1010 to 1130MPa and yet retains considerable total elongation in the range of 14–17%. The addition of Mn and Nb to DP steel leads to the maximum ultimate tensile strength, yield strength and the product of ultimate tensile strength and total elongation due to the formation of retained austenite and granular bainite structure. Laminar flow cooling after hot rolling results in a significant increase in the quantity of ferrite and bainite due to the suppression of pearlite transformation, and as a result, the present steel possesses high strengths and good toughness.


2011 ◽  
Vol 391-392 ◽  
pp. 1225-1229
Author(s):  
Cheng Gang Yang ◽  
Ge Ping Liu ◽  
Yu Hua Chen ◽  
Wei Ping Xu

The effect of single pulse, electromagnetic stirring plus single pulse on the microstructures and properties of high strength Al-Cu alloy welds is investigated. The results show that the grain structure of weld under conventional MIG welding are coarse, oriented columnar grains, the ultimate tensile strength of weld joint is 286.5 MPa, the elongation rate of joint is 2.4%. The thermal gradient at the solid-liquid interface in the welding pool is decreased and the density of heterogeneous nucleation is enhanced by electromagnetical stirring plus single pulse, which resulted in the coarse and oriented columnar grains transforming to fine equiaxed grains; morphology and distribution of α(Al)-CuAl2 eutectic along the grain boundaries are improved, so it significantly improves the mechanical property of weld joint, the ultimate tensile strength of weld joint is up to 326.0 MPa, the elongation rate of joint reaches 7.8%.


2016 ◽  
Vol 61 (2) ◽  
pp. 475-480
Author(s):  
K. Bolanowski

Abstract The paper analyzes the influence of different heat treatment processes on the mechanical properties of low-alloy high-strength steel denoted by Polish Standard (PN) as 10MnVNb6. One of the findings is that, after aging, the mechanical properties of rolled steel are high: the yield strength may reach > 600 MPa, and the ultimate tensile strength is > 700 MPa. These properties are largely dependent on the grain size and dispersion of the strengthening phase in the ferrite matrix. Aging applied after hot rolling contributes to a considerable rise in the yield strength and ultimate tensile strength. The process of normalization causes a decrease in the average grain size and coalescence (reduction of dispersion) of the strengthening phase. When 10MnVNb6 steel was aged after normalization, there was not a complete recovery in its strength properties.


2010 ◽  
Vol 654-656 ◽  
pp. 2728-2731 ◽  
Author(s):  
Je Sik Shin ◽  
Hyung Kwon Moon ◽  
Bong Hwan Kim ◽  
Hyo Soo Lee ◽  
Hyouk Chon Kwon

In this study, it was aimed to develop a novel interconnect material simultaneously possessing high electrical conductivity and strength. Combined structural Cu sheets were fabricated by forming the high electrical conduction paths of Ag on the surface of high strength Cu alloy substrate by damascene electroplating. As a result, the electrical conductivity increased by 40%, while the ultimate tensile strength decreased by only 20%. When the depth of Ag conduction path was deep, fracture zone ratio as well as roll-over zone increased.


2015 ◽  
Vol 789-790 ◽  
pp. 38-42
Author(s):  
Nuria S. Mohammed ◽  
Ahmed Baharuddin Abd Rahman ◽  
Nur Hafizah A. Khalid ◽  
Musaab Ahmed

Polymer resin grout can be used as bonding material for grouted sleeve connections This paper presents the experimental results on the effectiveness of fly ash as micro filler to the splitting tensile strength of polymer grout. In addition, the cement grout that is usually used as bonding material had been tested for comparison. Eleven proportions, of fly ash as the filler and polymer as binder, were tested with the binder to filler volume ratios of 1:1 and 1:1.5. The test results revealed that fly ash can be used as a micro-filler material to partially replace ordinary river sand in polymer resin grout. The splitting tensile strength of the polymer grout increases with the increase of fly ash contents. However, for higher level of fly ash of more than 22%, the splitting tensile strength deteriorated. For binder: filler ratio of 1:1, the optimum fly ash content of 22% gave the maximum splitting strength of 17.62 MPa, which can be considered acceptable for producing grout with high strength bonding material.


2016 ◽  
Vol 861 ◽  
pp. 147-152
Author(s):  
Fei Yang ◽  
Brian Gabbitas ◽  
Ajit Singh ◽  
Chung Fu Wang

In this paper, pure titanium rods, with high strength and ductility, were prepared by vacuum sintering titanium powder compacts at 1300oC for 2h and then hot extruding the as-sintered titanium billets at 900oC in air. The microstructure and property changes, after vacuum sintering and hot extrusion, were investigated. The results showed clear evidence of porosity in the microstructure of as-sintered titanium billet and tensile testing of as-sintered material gave yield strength, ultimate tensile strength and ductility values of 570MPa, 602MPa and 4%, respectively. After extrusion at 900oC, no obvious pores could be seen in the microstructure of as-extruded titanium rod, and the mechanical properties were significantly improved. The yield strength, ultimate tensile strength and the ductility reached 650MPa, 705MPa and 20%, respectively, which are much higher than values for CP titanium (grade 4), with a yield strength of 480MPa, ultimate tensile strength of 550MPa and ductility of 15%. The fracture characteristics of as-sintered and as-extruded titanium rods have also been investigated.


Author(s):  
Venkata Siva Teja Putti ◽  
S Manikandan ◽  
Kiran Kumar Ayyagari

Abstract Titanium (Ti-6Al-4V) is an α+β phase-field alloy utilized in many industries due to its high strength-to-weight ratio and near-net shaping capability. Solution treated & aging, and stress relief annealing processes were performed on the samples to increase the strength and % of elongation. The heat-treated samples then thermally cycled for 500 cycles, 1000 cycles, and 1500 cycles to evaluate the microhardness and tensile properties. The presence of martensite and α2 precipitates in the thermally cycled samples was confirmed by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). In this investigation, at 1000 thermal cycles, all specimens show improvement in both hardness and strength when compared within the cycles. Solution-treated and aging (STA), stress relief annealing (SRA), and without any heat-treatment (WHT) processes have their highest hardness values recorded for 1000 thermal cycles, and the values are 471 HV0.5, 381 HV0.5, and 374.6HV0.5, respectively. For the SRA process, ultimate tensile strength (UTS) of 925 MPa and yield strength (YS) of 896 MPa have resulted in 1000 cycles. Similarly, at 1000 thermal cycle WHT processed samples yielded UTS of 920 MPa and YS of 885 MPa. STA process samples that are heat-treated for 1000 thermal cycles have better strength properties than SRA and WHT and had a UTS of 1530MPa and YS of 1420MPa. From a ductility point of view, a maximum elongation of 29% for the STA process has resulted. Compared to forged titanium alloy (base metal), an increase of 31% elongation and 41% ultimate tensile strength for solution treated and aging process at 1000 cycles has resulted in this investigation.


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