scholarly journals Steel-Reinforced Polyethylene Pipe: Extrusion Welding, Investigation, and Mechanical Testing

2020 ◽  
Vol 99 (2) ◽  
pp. 52s-58s ◽  
Author(s):  
CHAYANEE TIPPAYASAM ◽  
◽  
ATTAPHON KAEWVILAI

This work presents extrusion welding with a square butt joint of V-shaped steel-reinforced polyethylene (SRPE) corrugated pipe. The SRPE pipe was welded in a single pass on the inside of the pipe. The welding temperature was controlled at 190°–200°C. The welding extruder was modified for controlling the travel speed and preheating conditions for welding. A high-density polyethylene (HDPE) rod was used as the welding filler metal, which was inserted into the extruder with a speed of 2.20 m/min. Welding progressed downhill from the overhead position with a travel speed of 3.0 cm/min. The effects of welding methods, with and without preheat conditions, on the weld quality were investigated by visual and radiographic inspections. From the results, the preheated welding condition showed complete fusion of the weld without any defects, while that of the nonpreheat exhibited a great number of voids inside the weld. The crystal structures of the preheated and nonpreheated welds were analyzed with an x-ray diffractometer and compared with the HDPE base material. From mechanical testing, the weld from the preheat condition showed a good ability to endure the tension force of 46 MPa and compressive stress of up to 0.41 MPa at 5%deflection. In addition, it was found the welded SRPE could tolerate hydrostatic pressure of up to 0.18 MPa without any water leakage when being used as a water-containing tank.

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.


2014 ◽  
Vol 657 ◽  
pp. 306-310
Author(s):  
Lăcrămioara Apetrei ◽  
Vasile Rață ◽  
Ruxandra Rață ◽  
Elena Raluca Bulai

Research evolution timely tendencies, in the nonconventional technologies field, are: manufacture conditions optimization and complex equipments design. The increasing of ultrasonic machining use, in various technologies is due to the expanding need of a wide range materials and high quality manufacture standards in many activity fields. This paper present a experimental study made in order to analyze the welded zone material structure and welding quality. The effects of aluminium ultrasonic welding parameters such as relative energy, machining time, amplitude and working force were compared through traction tests values and microstructural analysis. Microhardness tests were, also, made in five different points, two in the base material and three in the welded zone, on each welded aluminium sample. The aluminum welding experiments were made at the National Research and Development Institute for Welding and Material Testing (ISIM) Timişoara. The ultrasonic welding temperature is lower than the aluminium melting temperature, that's so our experiments reveal that the aluminium ultrasonic welding process doesn't determine the appearance of moulding structure. In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.


2018 ◽  
Vol 37 (5) ◽  
pp. 397-403 ◽  
Author(s):  
Shude Ji ◽  
Zhanpeng Yang ◽  
Quan Wen ◽  
Yumei Yue ◽  
Liguo Zhang

AbstractTrailing intensive cooling with liquid nitrogen has successfully applied to friction stir welding of 2 mm thick 2060 Al-Li alloy. Welding temperature, plastic strain, residual stress and distortion of 2060 Al-Li alloy butt-joint are compared and discussed between conventional cooling and trailing intensive cooling using experimental and numerical simulation methods. The results reveal that trailing intensive cooling is beneficial to shrink high temperature area, reduce peak temperature and decrease plastic strain during friction stir welding process. In addition, the reduction degree of plastic strain outside weld is smaller than that inside weld. Welding distortion presents an anti-saddle shape. Compared with conventional cooling, the reductions of welding distortion and longitudinal residual stresses of welding joint under intense cooling reach 47.7 % and 23.8 %, respectively.


2021 ◽  
Vol 875 ◽  
pp. 203-210
Author(s):  
Talha Ahmed ◽  
Wali Muhammad ◽  
Zaheer Mushtaq ◽  
Mustasim Billah Bhatty ◽  
Hamid Zaigham

In this study, mechanical properties of friction stir welded Aluminum Alloy (AA) 6061 in three different heat treatment conditions i.e. Annealed (O), Artificially aged (T6) and Post Weld Heat Treated (PWHT) were compared. Plates were welded in a butt joint form. Parameters were optimized and joints were fabricated using tool rotational speed and travel speed of 500 rpm and 350 mm/min respectively. Two sets of plates were welded in O condition and out of which one was, later, subjected to post weld artificial aging treatment. Third set was welded in T6 condition. The welds were characterized by macro and microstructure analysis, microhardness measurement and mechanical testing. SEM fractography of the tensile fracture surfaces was also performed. Comparatively better mechanical properties were achieved in the plate with PWHT condition.


2019 ◽  
Vol 813 ◽  
pp. 304-309
Author(s):  
Alejandro Oscar Miranda ◽  
Hernán Gabriel Svoboda

NiCrBSi coatings were produce by Flame Spray on a carbon steel substrate. The “as spray” coatings were refused by means of Pulsed Gas Tungsten Arc Welding (GTAW-P) process, following different patterns and welding procedure, with objective of optimize the coating characteristics and productivity. The patterns evaluated were oscillated triangular (OT) and oscillated sinusoidal (OS). Travel speed and workpiece-electrode distance were also analyzed. On each obtained sample the surface appearance, macro and microstructure on transverse cuts were evaluated, determining penetration, dilution and level of defects, among others features. Microhardness profiles and adherence were also evaluated. The OS pattern show a more uniform profile of the refused thickness, with less dilution with the base material. Travel speed and workpiece-electrode distance have both significant effect on the volume of refused material, affecting dilution and consequently the resultant coating hardness.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1937 ◽  
Author(s):  
Tomasz Machniewicz ◽  
Przemysław Nosal ◽  
Adam Korbel ◽  
Marek Hebda

The paper describes the influence of the friction stir welding travel speed on the mechanical properties of the butt joints of copper plates. The results of static and fatigue tests of the base material (Cu-ETP R220) and welded specimens produced at various travel speeds were compared, considering a loading applied both parallel and perpendicularly to the rolling direction of the plates. The mechanical properties of the FSW joints were evaluated with respect to parameters of plates’ material in the delivery state and after recrystallisation annealing. The strength parameters of friction stir welding joints were compared with the data on tungsten inert gas welded joints of copper plates available in the literature. The results of microhardness tests and fractographic analysis of tested joints are also presented. Based on the above test results, it was shown that although in the whole range of considered traverse speeds (from 40 to 80 mm/min), comparable properties were obtained for FSW copper joints in terms of their visual and microstructural evaluation, their static and especially fatigue parameters were different, most apparent in the nine-fold greater observed average fatigue life. The fatigue tests turned out to be more sensitive criteria for evaluation of the FSW joints’ qualities.


Author(s):  
Ottaviano Grisolia ◽  
Lorenzo Scano ◽  
Francesco Piccini ◽  
Antonietta Lo Conte ◽  
Massimiliano De Agostinis ◽  
...  

Abstract Previous study evaluated residual stress in a circumferential “V”-groove butt joint of a heat-recovery steam generator (HRSG) pipeline; the material was ASTM A-335-Grade P22. Aim had been to check on the influence over creep-relaxation previously found out for a tee made of the same material. The butt joint had been operating for the same period of 200,000 hours, same temperature of 528°C at almost a half pressure (0.46 Kg/mm2 vs. 1.06 Kg/mm2). X-ray diffraction (XRD) technique applied close to the weld highlighted anomalously high stress-level on the outer surface for all four butt-joint samples tested. Residual-stress over 400 MPa observed along the cylinder’s tangential direction was statically not acceptable. On the inner surface where deposited beads may have tempered adjacent base material, measurement via blind hole-drilling (BHD) technique showed a symmetrical plane-state residual-stress of 199 MPa. It was consistent with that observed via XRD on the outer surface in the cylinder’s longitudinal direction. Supposing a case of incomplete post heating planned for the weld may have explained the occurrence of being much higher than 40 MPa, value predicted after 200,000 hours. Similar influence over creep results found out for the tee and the butt joint had validated modeling welding simulation considered for both joints. A comprehensive new series of XRD tests aims now at measuring residual stress across the cylinder’s wall, both inner and outer sides. The shallow layer considered has thickness sufficient for building a map of measurements covering different depths and locations on the surface. The experimental plan includes also BHD tests supporting the XRD ones. Comparison with previous measurements roughly shows stress level increasing similarly across the cylinder’s wall from the inner side on: Average stress values, however, appear lower than previous measurements, showing better compatibility to the analysis results.


2016 ◽  
Vol 49 (6) ◽  
pp. 498-512 ◽  
Author(s):  
Ali Doniavi ◽  
Saeedeh Babazadeh ◽  
Taher Azdast ◽  
Rezgar Hasanzadeh

Although considerable progress has been made in recent years in field of polymer welding, challenges still remain in using a friction stir welding method to join polycarbonate (PC) composites. This research provides an investigation on the effect of welding parameters (tool’s travel and rotational speeds) on mechanical properties of PC nanocomposite weld lines. PC nanocomposites were prepared with different percentages of Al2O3 nanofiller using a twin screw extruder and injection moulded as sheets in order to ease the welding. Considering various parameters and their levels, optimization of Taguchi experimental design was carried out, an L16 orthogonal standard array was selected and the effective parameter was calculated using analysis of variance of the results. The results indicated that nanoalumina percentage is the most effective parameter on the tensile strength of weld and tool’s travel speed and rotational speed are next effective parameters, respectively. According to signal-to-noise ratio, maximum weld tensile strength (89.5% of base material) is revealed when nanoalumina percentage, tool’s travel speed and tool’s rotational speed were chosen as 1 wt%, 12 mm/min and 1250 r/min, respectively.


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