Local Postweld Heat Treatment of Heterogeneous Welded Joint

Abstract:

A concept of heterogeneous welded joint is proposed for researching and describing the characteristics of local postweld heat treatment (PWHT) temperature field for asymmetric thermal conductivity welded joint. Its three types have been classified according to thermal conductivity direction around the weld, separately, welded joint with transverse unidirectional thermal conductivity, transverse bidirectional thermal conductivity, transverse and longitudinal thermal conductivity. Compared with the temperature field of symmetric thermal conductivity welded joint, the highest temperature point of heterogeneous welded joint deviates from the heat device center, and uniform temperature area shrinks. In addition, longitudinal temperature difference and dramatic temperature change zone have arisen for the third type heterogeneous welded joint. In order to improve the temperature distribution, two PWHT methods called temperature compensation method and power compensation method have been put forward and developed. Several engineering applications of two methods are illustrated as examples.

• Periodical: Key Engineering Materials (Volume 730)
• Pages: 259-264
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.730.259
• Online since: February 2017
• Authors: Zhong Bing Chen*, Zhi Qiang Sun, Yi Shi Lv
• Keywords: Heterogeneous Welded Joint, Postweld Heat Treatment, Power Compensation Method, Temperature Compensation Method, Temperature Field

References

[1] Z. B. Chen, W. Q. Dai, M. Zhu, etc. Study of Stub Tube Weld Heat Treatment Temperature Field, Electr. Pow. Constr. 28 (2007) 63-67.

[2] J. Wang, J. Guo. Heat treatment procedure of special-shaped pieces in power plant, Tech. Innov. Appl. 12 (2014) 31.

[3] X. H. Xu, P. Qiu. Local PWHT and its temperature control of pipe and fittings welded joint. Weld. Join. 10 (1988) 14-18.

[4] L. Kou, L. B. Xin. Welding and PWHT procedure of different diameter & dissimilar steel welded joint, Mod. Weld. 4 (2014) 41-44.

[5] Z. B. Chen, Z. Q. Sun. A PWHT method of unequal size pipeline welded joint, China Patent ZL 201110358082. 3. (2013).

[6] Z. B. Chen, Z. Q. Sun, Y. S. LV. A local PWHT method of main tee pipe butt welded joint, China Patent ZL 201410403195. 4. (2016).

[7] Z. B. Chen, C. P. Tang, Z. Q. Sun, etc. A local PWHT method of main tee pipe butt welded joint, China Patent ZL 201410404328.X. (2016).

[8] Z. B. Chen, Y. S. LV, Z. Q. Sun. A local PWHT method of stub tube butt welded joint, China Patent ZL 201410404469. 1. (2016).

[9] Z. B. Chen, Y. S. LV, Z. Q. Sun. A local PWHT method of stub tube fillet welded joint, China Patent ZL 201410403663. 8. (2016).

[10] Z. B. Chen, Z. Q. Sun, S. M. Zhang, etc. A local PWHT method of tee branch pipe butt welded joint, China Patent ZL 201410403337. 7. (2016).

[11] Z. B. Chen, Y. S. LV, Z. Q. Sun. A local PWHT method of stub tube butt welded joint, China Patent ZL 201410403336. 2. (2016).

[12] W. H. Cai, W. D. Zhao, Z. C. Wang, etc. Softening mechanism and heat treatment process control of P91 steel used for steam pipe, Therm. Pow. Gener. 42 (2013) 23-25.

[13] Z. B. Chen, Y. F. Zhao, J. C. Zhao, etc. Analysis and Controlling for Cracks in Welded Joint of Thick Walled Steel 12Cr1MoVG. Proc. CSEE, 32 (2012) 137-143.

[14] X. M. Zhang, Z. P. Ren, F. M. Mei. Heat Transfer (5th Eds. ), China Building Industry Press, Beijing, (2007).