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Heat-affected zone

About: Heat-affected zone is a research topic. Over the lifetime, 18787 publications have been published within this topic receiving 231744 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a central fusion weld joint reinforced by TiC, Ti5Si3 and Al3Ti is produced by in-situ weld-alloying/laser beam welding of SiCp/6061Al MMC, while some large pores are formed in the partly melted zone.
Abstract: In this paper, ‘in-situ’ weld-alloying/laser beam welding with titanium as alloying element is utilized to join SiCp/6061Al MMC in order to prevent the formation of the needle-like harmful Al4C3 phases in the weld. Microstructure of the weld is characterized as functions of alloying content and processing parameters. Results show that the needle-like harmful aluminum carbides are completely eliminated. A central fusion weld joint reinforced by TiC, Ti5Si3 and Al3Ti is produced by ‘in-situ’ weld-alloying/laser beam welding of SiCp/6061Al MMC, while some large pores are formed in the partly melted zone.

60 citations

Journal ArticleDOI
TL;DR: In this article, the microstructural responses of P91 pipe weldments have been characterized in as-welded, postweld heat treatment (PWHT) and ageing conditions.
Abstract: Steels 9-12% Cr, having the high creep rupture strength are advocated for the modern low polluting thermal power plants. In the present investigation, the P91 pipe weldments have been characterized for microstructural responses in as-welded, post-weld heat treatment (PWHT) and ageing conditions. The PWHT of welded samples were carried out at 760 °C for time of 2 h and ageing at 760 °C for 720 h and 1440 h, respectively. The effect of time has been studied on precipitates size, distribution of precipitates and grain sizes present in various zones of P91 steel weldments. The impact toughness and hardness variation of heat affected zone (HAZ) have also been studied in as-welded condition as well as at different heat treatment condition. A significant change was observed in grain size and precipitates size after each heat treatment condition. The maximum impact toughness of HAZ was obtained after PWHT at 760 °C for 2 h. The main phase observed in weld fusion zone in as-welded, PWHT and ageing conditions were M23C6, MX, M7C3, Fe-rich M3C and M2C. The unwanted Z-phase (NbCrN) was also noticed in weld fusion zone after ageing of 1440 h.

60 citations

Patent
24 Dec 1984
TL;DR: In this paper, a weld metal cooling rate indication system is provided for a welding mace, which is capable of producing a weld bead and has a speed sensor which senses the speed at which the torch travels as selected by an operator.
Abstract: A weld metal cooling rate indication system is provided for a welding mace. The welding machine has a torch which is capable of producing a weld bead and has a speed sensor which senses the speed at which the torch travels as selected by an operator. The indication system includes a device for continuously sensing a profile of temperatures along the weld bead, this profile including a predetermined weld temperature. Another device receives the temperature profile and travel speed of the torch information for calculating and producing a signal which represents rate of change of weld temperature at the predetermined weld temperature. A range of acceptable rates of change of weld temperatures at the predetermined weld temperature is provided so that the rate of change of weld temperature at the predetermined weld temperature can be compared with this range. A device is then provided which is responsive to the comparing information for indicating whether the rate of change of weld temperature is within, above, or below the range of acceptable rates of change of weld temperatures. With this arrangement the welding operator can adjust the speed of the welding torch so that a proper rate of change of weld temperature is maintained at all times to increase the quality of the weld.

60 citations

Journal ArticleDOI
TL;DR: In this paper, a 3-factor, 5-level welding experiment is conducted by Taguchi L25 orthogonal array through the statistical design method, and the output results are efficient connection length of left side and right side, top width (WT) and bottom width (WB) of the weld bead.

60 citations

Journal ArticleDOI
TL;DR: In this paper, a double-electrode gas metal arc welding (DE-GMAW) was developed to increase the melting current while the base metal current can still be controlled at a desired level.
Abstract: Gas metal arc welding (GMAW) is the most widely used process for metal joining because of its high productivity and good quality, but analysis shows that the fundamental characteristic restricts conventional GMAW from further increasing the welding productivity. A novel GMAW process, refereed to as double-electrode GMAW or DE-GMAW, thus has been developed to make it possible to increase the melting current while the base metal current can still be controlled at a desired level. This fundamental change provides an effective method to allow manufacturers to use high melting currents to achieve high melting speed and low base metal heat input. A series of experiments have been conducted to uncover the basic characteristics of this novel process. Results obtained from analyses of high-speed image sequences and recorded current signals suggest that DE-GMAW can lower the critical current for achieving the desired spray transfer, shift the droplet trajectory, reduce the diameter of the droplet, and increase the speed and (generation) rate of the droplets.

60 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023229
2022548
2021270
2020365
2019389
2018463