A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Chinoy, Nimesh
- Air-Cooled Induction Heating Solution for Heat Treatment of P91 Grade Steel in Welding Applications
Authors
1 Electronics Devices (World Wide) Private Limited 22 Mistry Industrial Estate, Cross Road A MIDC, Andheri (E), Mumbai - 400093, IN
Source
Indian Welding Journal, Vol 51, No 3 (2018), Pagination: 81-88Abstract
To have long operating life and to withstand high temperature and pressure of steam, now a days, the standard material used in power industry is the P91 Grade steel. It has high creep resistance. In a fabrication process when arc welding is used for joining this material the high energy density of arc heat makes strong influence on its microstructure. Moreover, the prospect of hydrogen cracking increases if pre-heating is not properly done. Therefore, for long term quality of P91 Grade steel, detailed heat treatment operation must be performed before and after the welding. For heat treatment operations, the induction heating method is ideally suitable. This article proposes to use air-cooled system to improve the efficiency of power delivery to the requisite area of pipe in high power applications.Keywords
Post Weld Heat Treatment (PWHT), Programmable Logic Controller (PLC), Self-tuning Controller, Wide Range Induction Heating, Zero Voltage And Near Zero Current Switching (ZVS-N-ZCS).References
- Coleman KK and Newell Jr. WF (2007); P91 and Beyond, Welding Journal, 86(8), pp. 29-33.
- Taniguchi G and Yamashita K (2013); Effects of post weld heat treatment (PHWT) temperature on mechanical properties of weld metals for high-Cr Ferritic heat-resistant steel, Kobelco Technology Review, 32, pp. 33-39.
- Post weld heat treatment of welded structures, Guidance note 6, WTIA-Panel 1, pp. 1-10.
- Ahmed K and Krishnan J (2003); Post weld heat treatment – A case studies, BARC Newsletter, pp. 111-114.
- Messler Jr. RW (2004); Principles of Welding, WileyVCH, Verlog, ISBN 9780471253761.
- Chaboudez C et al (1994); Numerical modelling of induction heating of long work pieces, IEEE Trans.
- Mag., 39(6), pp.5028-5037.
- Skoczkowski TP and Kalus MF (2003); The mathematical model of induction heating of ferromagnetic pipes, IEEE Trans. Mag., 25(3), pp. 2745-2750.
- Paul AK (2018); Active-controlled passive distribution of power offers efficient heat treating solution for quality arc welding joints of steel pipes, IEEE Trans. Ind. Appln., Early Access.
- Fujita, H et al (2011); A new zone-control induction heating system using multiple inverter units applicable under mutual magnetic coupling conditions, IEEE Trans. Power Electron., 26(7), pp. 2009 – 2017.
- Paul AK and Chinoy SB (2016); Air cooled induction heater for efficient sealing of containers using wide range foils, IEEE Trans. Ind. Appln., 52(2), pp. 3398-3407.
- Paul AK (2017); Robust control by SOSM facilitates optimizing under actuated induction cap sealing process, IEEE Trans. Ind. Electron., 64(6), pp. 45114519.
- Mishima T, Takami C and Nakaoka M (2014); A new current phasor-controlled ZVS twin half-bridge highfrequency resonant inverter for induction heating, IEEE Trans. Ind. Electron., 61(5), pp. 2531 – 2545.
- Koertzen HW, van Wyk JD and Ferreira, JA (1992); An investigation of the analytical computation of inductance and ac resistance of the heat-coil for induction cookers, Conf. Proc IEEE IAS, pp. 1113 – 1119.
- Paul AK (2018); Robust features of SOSMC guides in quality characterization of tank circuit in air-cooled induction cap sealing, IEEE Trans. Ind. Appln., 54(1), pp. 755-763.
- Meziane B and Zeroug H (2015); Improved efficiency determination for a PLL-controlled series resonant inverter for induction metal surface hardening, Conf. Proc. IEEE Ind. Appl. Ann. Meeting, pp. 1 – 8.
- Paul AK (2010); Comparative study of functional integrity on major topologies for induction heating equipment, Conf. Proc. IEEE PEDES, New Delhi, India, pp. 1-6.
- Solving Critical Issues at Low Current in TIG Welding by Controlling Levels of Saturation at the Input of the Inverter
Authors
Source
Indian Welding Journal, Vol 41, No 1 (2008), Pagination: 27-33Abstract
The operating current range for TIG welding is wide. Welding at very low current in TIG mode is common. However, managing low current operation in dynamic situation is critical. High frequency inverter has the extra ability to take care some of these problems to a great extent. To meet such requirement(s), the amplifier for the inverter is normally a ‘P+I’ controller with large DC gain. The bandwidth of this type of inverters is limited by the presence of lag compensating elements of the controller. However, lag compensator with ‘controlled peak current mode control’ can develop, to our advantage, ‘wind-up’ in the controller to bring benefits on the dynamical aspects for TIG welding inverters at lower current setting. This paper would discuss the issues of TIG welding at low operating current and also demonstrate how wind-up is created to eliminate the problematic issues. It is absolutely critical for non-contact TIG welding inverter.