Dongkuk Steel cold-rolled galvanized and color steel sheet affiliate Dongkuk CM said on the 30th it has successfully developed DK SDD (Surface Defect Detector), an artificial intelligence (AI)-based technology that can detect defects on steel sheet surfaces.
Inspecting surface defects on color steel sheets had relied on inspectors visually checking each steel coil as long as 5,000 meters, but high-resolution cameras capable of real-time image inspection can now replace that process. The speed has also been increased so defects can be effectively captured even during high-speed production at 130 meters per minute.
DK SDD blends rule-based techniques with deep learning, adding automatic learning of product image characteristics to the definition and classification of nonconforming images, making it applicable even to premium color steel sheets with uneven surfaces and more than 20,000 colors mixed in.
As a result, it is designed to reliably detect only defects even on design-pattern color steel sheets, where the surface itself is likely to be mistaken for a defect under existing technologies. Dongkuk CM said this was thanks to the original technology secured after more than three years of continuous research and development, and noted it is preparing to file a patent.
Dongkuk CM expects that applying the technology will improve the quality competitiveness of color steel sheets, enable early detection and prevention of recurring anomalies, and facilitate the accumulation and management of quality histories.
DK SDD has been applied to 2CCL, which produces high-speed construction color steel sheets at Dongkuk CM's Busan plant, completing commercialization, and is undergoing performance verification tests on 5CCL and 7CCL, the production lines for premium home appliance color steel sheets.
The company will push full-scale commercialization in the second half of this year and apply DK SDD to all color steel sheet production lines at the Busan plant by next year. It plans to design the system to automatically link inspection results with the Manufacturing Execution System (MES) to systematically accumulate and manage quality histories.
Choi Woo-chan, head of the Dongkuk CM Technology Research Center, said, "We have set a new standard for surface quality inspection of color steel sheets," and added, "We will not stop at enhancing the competitiveness of color steel sheet products; we will build a sustainable manufacturing environment through process automation and technological advancement, and continue to pursue the realization of an AI-based intelligent factory."