The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
S Genna - One of the best experts on this subject based on the ideXlab platform.
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Heat Affected Zone extension in pulsed nd yag laser cutting of cfrp
Composites Part B-engineering, 2018Co-Authors: Claudio Leone, S GennaAbstract:Abstract Laser cutting is a promising alternative to the traditional methods in CFRP cutting. However, laser cutting is based on thermal interaction that results in thermal damages of both matrix and fibres. The Heat Affected Zone (HAZ) extension is strictly dependent on the adopted laser source and the working parameters. The paper presents an experimental study on the laser cutting of CFRP plate, 1 mm in thickness by means of 150 W Nd:YAG pulsed laser. The cutting region and the influence of process parameters, pulse energy, pulse duration and overlapping, on the kerf geometry and the HAZ were analyzed. Experimental results showed that the adopted laser is able to cut the CFRP plate, up to 10.8 mm/s. However, an accurate selection of the process parameters is necessary in order to obtain the maximum cutting speed and a narrow HAZ. Moreover, a relation between the HAZ extension and the process parameters (average power, cutting speed, pulse frequency and pulse duration) was found.
S Moeinifar - One of the best experts on this subject based on the ideXlab platform.
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influence of thermal simulated and real tandem submerged arc welding process on the microstructure and mechanical properties of the coarse grained Heat Affected Zone
Applied Mechanics and Materials, 2011Co-Authors: S MoeinifarAbstract:The high-strength low-alloy microalloyed steel was procured as a hot rolled plate with accelerated cooling. The Gleeble thermal simulated process involved Heating the steel specimens to the peak temperature of 1400 °C, with constant cooling rates of 3.75 °C/s and 2 °C/s to room temperature. The four-wire tandem submerged arc welding process, with different Heat input, was used to generate a welded microstructure. The martensite/austenite constituent appeared in the microstructure of the Heat Affected Zone region for all the specimens along the prior-austenite grain boundaries and between bainitic ferrite laths. The blocky-like and stringer martensite/austenite morphology were observed in the Heat Affected Zone regions. The martensite/austenite constituents were obtained by a combination of field emission scanning electron microscopes and image analysis software The Charpy absorbed energy of specimens was assessed using Charpy impact testing at-50 °C. Brittle particles, such as martensite/austenite constituent along the grain boundaries, can make an easy path for crack propagation. Similar crack initiation sites and growth mechanism were investigated for specimens welded with different Heat input values.
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role of tandem submerged arc welding thermal cycles on properties of the Heat Affected Zone in x80 microalloyed pipe line steel
Journal of Materials Processing Technology, 2011Co-Authors: S Moeinifar, A H Kokabi, H Madaah R HosseiniAbstract:Abstract The influence of thermal cycles on the properties of the coarse grained Heat Affected Zone in X80 microalloyed steel has been investigated. The thermal simulated involved Heating the X80 steel specimens to the peak temperature of 1400 °C, with different cooling rates. The four-wire tandem submerged arc welding process, with different Heat input values, was used to generate a welded microstructure. The martensite/austenite constituent appeared in the microstructure of the Heat Affected Zone region for all the specimens along the prior-austenite grain boundaries and between the bainitic ferrite laths. The blocky-like and stringer martensite/austenite morphology were observed in the Heat Affected Zone region. The fractional area of M/A particles due to different cooling rate was the main factor in increasing of the hardness values in the coarse grained Heat Affected Zone. The Charpy absorbed energy of specimens was assessed using Charpy impact testing at −50 °C. The martensite/austenite constituent's size such as mean diameter and length are important factors influencing Charpy impact properties of coarse grained Heat Affected Zone. The micro crack nucleation may occur from M/A particles at the intersection of prior-austenite grain boundaries. Similar crack initiation sites and growth mechanism were investigated for specimens welded with different Heat input values.
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influence of four wires tandem submerged arc welding process on Heat Affected Zone properties in high strength pipeline steel
2010Co-Authors: S Moeinifar, A H Kokabi, Hamid Reza Madaah Hosseini, Chengjia J Shang, Gou Hui, Liu Zhen WeiAbstract:The objective of this investigation was to provide a detailed evaluation of the Heat Affected Zone properties of a high-strength pipeline steel. The X80 high-strength low-alloy microalloyed steel was supplied as a hot rolled plate with accelerated cooling. The four-wire tandem submerged arc welding process with different Heat input was used to generate welded joints. The microstructure of the Heat Affected Zone depended on Heat input values. M/A constituent appeared in the microstructure of HAZ region for all of the specimens along the prior-austenite grain boundaries and between bainitic ferrite laths. Charpy impact specimens were notched in four locations: FL (fusion line), FL+1mm, FL+2mm and FL+3mm. The Charpy absorbed energy of specimens was assessed using Charpy impact testing at -50°C.
H Madaah R Hosseini - One of the best experts on this subject based on the ideXlab platform.
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role of tandem submerged arc welding thermal cycles on properties of the Heat Affected Zone in x80 microalloyed pipe line steel
Journal of Materials Processing Technology, 2011Co-Authors: S Moeinifar, A H Kokabi, H Madaah R HosseiniAbstract:Abstract The influence of thermal cycles on the properties of the coarse grained Heat Affected Zone in X80 microalloyed steel has been investigated. The thermal simulated involved Heating the X80 steel specimens to the peak temperature of 1400 °C, with different cooling rates. The four-wire tandem submerged arc welding process, with different Heat input values, was used to generate a welded microstructure. The martensite/austenite constituent appeared in the microstructure of the Heat Affected Zone region for all the specimens along the prior-austenite grain boundaries and between the bainitic ferrite laths. The blocky-like and stringer martensite/austenite morphology were observed in the Heat Affected Zone region. The fractional area of M/A particles due to different cooling rate was the main factor in increasing of the hardness values in the coarse grained Heat Affected Zone. The Charpy absorbed energy of specimens was assessed using Charpy impact testing at −50 °C. The martensite/austenite constituent's size such as mean diameter and length are important factors influencing Charpy impact properties of coarse grained Heat Affected Zone. The micro crack nucleation may occur from M/A particles at the intersection of prior-austenite grain boundaries. Similar crack initiation sites and growth mechanism were investigated for specimens welded with different Heat input values.
Zhuguo Li - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Heat Affected Zone liquation cracking in laser additive manufacturing of Inconel 718
Materials & Design, 2016Co-Authors: Yuan Chen, Ke Zhang, Seyed Reza Elmi Hosseini, Zhuguo LiAbstract:Abstract The Heat Affected Zone liquation cracking behavior was studied in laser additive manufactured Inconel 718. Liquation cracking was found initiating from the weak site near the fusion line in the pre-deposited layer, propagating along the interdendritic region with the further deposition proceeding layer by layer. Total cracking length calculation results showed that when controlling the Heat input and height increment constant, liquation cracking susceptibility increased with the increase of laser scanning speed; and when controlling the laser scanning speed and height increment constant, liquation cracking susceptibility increased with the increase of Heat input. The effect of grain boundary misorientation on susceptibility to liquation cracking was also investigated through electron backscatter diffraction (EBSD) measurement, and the results showed that liquation cracking tendency increased with the increase of grain boundary angle, which was considered to be attributed to the higher stability of liquation film at larger grain boundary during the last stage of solidification.
Tetsuo Shoji - One of the best experts on this subject based on the ideXlab platform.
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characterization of microstructure local deformation and microchemistry in alloy 600 Heat Affected Zone and stress corrosion cracking in high temperature water
Corrosion Science, 2012Co-Authors: Zhanpeng Lu, Tetsuo Shoji, Seiya Yamazaki, Kazuhiro OgawaAbstract:Abstract With increasing the distance from the weld fusion line in an Alloy 600 Heat-Affected Zone, kernel average misorientation decreases and the fraction of Σ3 boundaries increases. Cr 7 C 3 carbides mainly precipitate at random high angle boundaries. Chromium depletion and segregation of boron and phosphorous at grain boundaries are observed. Alloy 600 Heat-Affected Zone specimens exhibit higher intergranular stress corrosion cracking growth rates than that in the base metal in simulated pressurized water reactor water environments. Crack growth rate is enhanced by strain hardening and by increasing temperature. The role of stress on interface oxidation kinetics is analyzed.
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characterization of microstructure and local deformation in 316ng weld Heat Affected Zone and stress corrosion cracking in high temperature water
Corrosion Science, 2011Co-Authors: Tetsuo Shoji, Fanjiang Meng, He Xue, Yubing Qiu, Yoichi Takeda, Koji NegishiAbstract:Abstract Microstructure and local deformation in 316NG weld Heat-Affected Zones were measured by electron-back scattering diffraction and hardness measurements. With increasing the distance from the fusion line, kernel average misorientation decreases and the fraction of Σ3 boundaries increases. Stress corrosion cracking growth rates in high temperature water were measured at different locations in the Heat-Affected Zones that correspond to different levels of strain-hardening represented by kernel average misorientation and hardness distribution. Intergranular cracking along random boundaries as well as extensive intergranular crack branching is observed in the Heat-Affected Zone near the weld fusion line.
