Prior to the 1970s, research focused on pulsed laser welding (PW) because high-power continuous-wave (CW) lasers had not yet been developed. Early experiments primarily utilized pulsed ruby lasers, characterized by a typical peak output power ($P_m$) of approximately 5 kW for a 1 ms pulse, pulse energy of 1–5 J, and a pulse frequency of 1 Hz or less. Although high pulse energies could be achieved, the average output power ($P$) of these lasers was quite low, a limitation largely dictated by the lasers' low operating efficiency and the stimulated emission characteristics of the lasing medium. Once lasers capable of higher average power emerged, they quickly became the preferred equipment for spot and seam welding-processes achieved through the overlapping of individual weld spots. However, true laser seam welding only became feasible with the advent of continuous-wave lasers exceeding 1 kW in power.
Current Status and Prospects of Welding Automation Technology
As digital technology matures, digital welding machines and digital control systems-key components of automated welding technology-have steadily entered the market. Major national infrastructure projects-such as the Three Gorges Project, the West-to-East Gas Pipeline Project, aerospace initiatives, and shipbuilding programs-have effectively driven the advancement of advanced welding technologies, particularly welding automation. Requirements for the level of welding automation in the automotive and auto-parts manufacturing sectors are evolving rapidly. my country's welding industry is gradually moving toward high efficiency, automation, and intelligence. Currently, my country's welding automation rate is below 30%, lagging significantly behind the 80% rate seen in developed industrial nations. Since the late 20th century, the state has promoted gas-shielded welding-a foundational automated welding method-across various industries to replace traditional manual arc welding, a move that has already yielded initial results. Domestic automated welding technology is expected to develop at an unprecedented pace in the future.
Current Status of High-Efficiency, Automated Welding Technology
In the 1990s, my country's welding sector adopted the mechanization and automation of welding processes as a strategic goal, implementing this objective through technological development across various industries. Efforts have focused on advancing automated welding production, researching and developing welding production lines and flexible manufacturing technologies, and applying computer-aided design and manufacturing (CAD/CAM). The market share of flux-cored wire has grown from 2% to 20%, and the consumption of submerged arc welding consumables is projected to continue growing from its current level of 10%. Among these, the growth rate of flux-cored welding wire is accelerating significantly; it is projected to surpass solid welding wire within the next 20 years and ultimately become the dominant product in the welding sector.
Prospects for Welding Automation Technology
Advancements in electronics, computer microelectronics, information technology, and automation have driven the progress of welding automation. In particular, the introduction of enabling technologies-such as numerical control (NC), flexible manufacturing, and information processing-has catalyzed a revolutionary evolution in welding automation.
(1) The intelligentization of welding process control systems is a core issue in welding automation and a key direction for future research. We must investigate optimal control methods, encompassing both linear and various nonlinear control strategies. Representative examples include research into fuzzy control, neural network control, and expert systems for the welding process.
(2) Welding flexibility technology is another major focus of our research. Future efforts will organically integrate optical, mechanical, and electrical technologies with welding processes to achieve greater precision and flexibility. Upgrading traditional welding equipment with microelectronics is fundamental to advancing welding automation. One current research direction involves equipping various welding machines with NC technology to enhance flexibility. Additionally, we are prioritizing the integration of welding robots with expert systems to enable functions such as automatic path planning, trajectory correction, and weld penetration control.
(3) Integrating welding control systems involves both human-technology integration and the convergence of welding technology with information technology. Information flow and material flow are critical components of these integrated systems; their organic combination can significantly reduce data volume and real-time control demands. It is also crucial to leverage human capabilities-specifically responsiveness and judgment in control and ad-hoc decision-making-and to establish user-friendly human-machine interfaces that foster harmony between human operators and automated systems.
(4) Improving the reliability, quality stability, control precision, and dynamic performance of welding power sources is another key research priority. We aim to develop high-performance welding machines capable of regulating arc motion, wire feeding, and torch orientation, while also detecting weld groove geometry, temperature fields, weld pool dynamics, and penetration status to provide real-time welding parameters. Furthermore, we must actively develop computer simulation technologies for the welding process. Transforming welding technology from a "craft" into a "science" represents a vital aspect of achieving welding automation. The first decade of this century will be a period of rapid development for the welding industry. We in the welding profession face a challenging yet significant mission; we must be determined to overcome obstacles, seize opportunities, and strive to advance the level of welding automation in our country.
