Chapter 10
A Novel High-Efficiency Keyhole
Tungsten Inert Gas (K-TIG) Welding:
Principles and Practices
Yonghua Shi, Yanxin Cui, Shuwan Cui, and Baori Zhang
Abstract As an innovation of the conventional Tungsten Inert Gas (TIG) welding,
Keyhole Tungsten Inert Gas (K-TIG) welding is highly efficient, well-known for its
penetration ability and welding quality. In this chapter, the K-TIG welding is introduced, including its equipment, operation methods, the influence of welding parameters and application extensions. Then, the keyhole stability rules are discussed, so
do the arc forces and heat input. To obtain a deeper insight into the welding process,
experiments on Ti alloy are carried out, from which the arc current signal, arc voltage
signal and arc acoustic signal are collected synchronously. Some characteristics are
extracted from the collected signals, by which the welding process is analyzed quantitatively. After the careful analysis of K-TIG welding process, a welding penetration
recognition model is established, which shows a good performance. Finally, to evaluate K-TIG welding, experiments are performed on duplex stainless steels and Ti
alloys. The effect of the welding parameters on the weld geometry profile and the
misorientation angle distribution of grain boundary are discussed. The microstructure and mechanical properties of weldments are evaluated. All of the testing results
verify the perfect performance and welding quality of K-TIG welding.
Keywords K-TIG · Welding parameters · Keyhole stability · Arc forces · Heat
input · Signal processing · Penetration recognition · MADGB · Microstructure ·
Mechanical properties
10.1 Overview
10.1.1 High Current Tungsten Inert Gas (TIG) Welding
As a highly efficient way of welding, GTAW has been widely used to produce highquality joints with various materials. By using low fume generation and requiring
Y. Shi (B) · Y. Cui · S. Cui · B. Zhang
School of Mechanical and Automotive Engineering, South China University of Technology,
Guangzhou 510640, China
e-mail: yhuashi@scut.edu.cn
© Springer Nature Switzerland AG 2021
J. P. Davim (ed.), Welding Technology, Materials Forming, Machining
and Tribology, https://doi.org/10.1007/978-3-030-63986-0_10
313
A Novel High-Efficiency Keyhole
Tungsten Inert Gas (K-TIG) Welding:
Principles and Practices
Yonghua Shi, Yanxin Cui, Shuwan Cui, and Baori Zhang
Abstract As an innovation of the conventional Tungsten Inert Gas (TIG) welding,
Keyhole Tungsten Inert Gas (K-TIG) welding is highly efficient, well-known for its
penetration ability and welding quality. In this chapter, the K-TIG welding is introduced, including its equipment, operation methods, the influence of welding parameters and application extensions. Then, the keyhole stability rules are discussed, so
do the arc forces and heat input. To obtain a deeper insight into the welding process,
experiments on Ti alloy are carried out, from which the arc current signal, arc voltage
signal and arc acoustic signal are collected synchronously. Some characteristics are
extracted from the collected signals, by which the welding process is analyzed quantitatively. After the careful analysis of K-TIG welding process, a welding penetration
recognition model is established, which shows a good performance. Finally, to evaluate K-TIG welding, experiments are performed on duplex stainless steels and Ti
alloys. The effect of the welding parameters on the weld geometry profile and the
misorientation angle distribution of grain boundary are discussed. The microstructure and mechanical properties of weldments are evaluated. All of the testing results
verify the perfect performance and welding quality of K-TIG welding.
Keywords K-TIG · Welding parameters · Keyhole stability · Arc forces · Heat
input · Signal processing · Penetration recognition · MADGB · Microstructure ·
Mechanical properties
10.1 Overview
10.1.1 High Current Tungsten Inert Gas (TIG) Welding
As a highly efficient way of welding, GTAW has been widely used to produce highquality joints with various materials. By using low fume generation and requiring
Y. Shi (B) · Y. Cui · S. Cui · B. Zhang
School of Mechanical and Automotive Engineering, South China University of Technology,
Guangzhou 510640, China
e-mail: yhuashi@scut.edu.cn
© Springer Nature Switzerland AG 2021
J. P. Davim (ed.), Welding Technology, Materials Forming, Machining
and Tribology, https://doi.org/10.1007/978-3-030-63986-0_10
313