Development and Application of Laser-Arc Hybrid Welding Technology for High-End Continuous Plate and Strip Production Lines

Project Overview: The welding machine is one of the core components of the continuous plate and strip production line, integrating optics, mechanics, electronics, hydraulics, and pneumatics. Its welding quality directly determines whether the production line can operate continuously and stably.

With the development of the national economy and increasing demands for energy conservation and emission reduction, there is a growing need for advanced special metallurgical materials such as high-strength steel, high-chromium stainless steel, high-magnetic silicon steel, and non-ferrous metals. However, these materials present significant challenges in welding, such as severe weld seam embrittlement and frequent strip breakage. These issues have raised higher requirements for welding process reliability and equipment precision. For a long time, imported laser welding machines have been used for these materials. However, these machines are costly and primarily use CO₂ gas lasers, which come with significant disadvantages: complex structures, high maintenance costs, and expensive operation.

In the past decade, solid-state lasers, represented by fiber and disk lasers, have gradually replaced traditional CO₂ gas lasers in industrial production due to their high photoelectric conversion efficiency, flexible beam delivery, stability, and lower maintenance and production costs. The original welding processes designed for CO₂ gas lasers can no longer meet the production requirements for advanced special metallurgical materials, creating an urgent need to develop new welding processes and equipment.

After nearly ten years of independent research and development, the project team at MCC South has overcome a series of technical challenges in welding processes and equipment. They have tackled the poor weldability, plate shape defects, and difficulties in achieving stable welding quality of special metallurgical materials. This effort led to the successful development of a laser-arc hybrid welding machine for high-end continuous plate and strip production lines, utilizing solid-state lasers. This innovative solution enables the welding of difficult materials such as high-magnetic silicon steel and martensitic stainless steel, achieving successful production applications.

Key Innovations and Achievements:

1. Development of Laser-Arc Hybrid Welding Process and Equipment: This innovative technology is specifically designed for high-end special metallurgical materials in continuous production lines. It ensures exceptional welding reliability, achieving a strip breakage rate of less than 0.1% and a re-welding rate below 1.2%.

2. Guided Welding Head Technology: For the first time, welding head guidance and positioning technology were developed, improving the working environment for the welding head, enhancing process stability, and extending the service life of the welding head.

3. Piano-Key Spring Press Plate Technology: The project introduced a pioneering piano-key spring press plate system, which evenly distributes force across the width of the plate and strip. Compared to traditional clamping methods, this eliminates plate defects such as edge warping and undercuts, significantly improving weld seam quality and stability.

The project has secured 7 patents, including 2 invention patents, and published 5 academic papers. The China Metallurgical Group’s evaluation committee recognized the results, affirming that the project has achieved an “internationally advanced level.”

The solid-state laser-arc hybrid welding machine developed by MCC South offers stable performance, superior welding quality, low operational costs, and simple maintenance. Its overall investment cost is only about one-third that of imported laser welding machines. To date, 15 units have been successfully implemented in leading steel enterprises such as Baosteel, Maanshan Iron & Steel, JISCO, TISCO, and Tsingshan Steel. These welding machines have been used to weld challenging materials, including high-strength steel, high-magnetic silicon steel, high-chromium stainless steel, and titanium plates. In particular, for high-magnetic silicon steel and martensitic stainless steel, the domestic market share of MCC South's laser welding machines has reached 100%.

This groundbreaking achievement marks a significant step forward in advancing China’s independent innovation capabilities, reducing reliance on imported equipment, and supporting the development of high-end special metallurgical materials in the global market.