Gwangyang Steelworks Saves 10 Billion KRW by Increasing Hot Slab Continuous Rolling Rate

Maximizing Energy Efficiency Through Scheduling AI Automation

POSCO Gwangyang Steelworks announced on September 23 that it has succeeded in reducing costs by approximately 10 billion KRW through the "increase in hot slab (HCR) continuous rolling rate," achieving both improved productivity and energy savings.

At the Gwangyang Steelworks casting plant, both hot slabs with temperatures above 300 degrees Celsius and cold slabs (CCR) at lower temperatures are produced. Each slab coming out of the caster is put into a hot furnace to be processed into a softer state to facilitate rolling.

Panoramic view of Gwangyang Steelworks.

In the case of cold slabs with lower temperatures, more energy is required because hot air must be blown in to raise them to the appropriate temperature, resulting in higher energy consumption compared to heating hot slabs.

To reduce such inefficiencies and lower energy costs, Gwangyang Steelworks developed a technology to maximize the continuous rolling rate of hot slabs by separating hot and cold slabs and ensuring stable, continuous heating.

This model, developed under the leadership of the Production Technology Department at Gwangyang Steelworks, is centered on a schedule automation system. The AI-based automation model optimizes the rolling order and other variables to maximize the continuous rolling rate of hot slabs. As a result, the rolling rate for hot slabs improved by approximately 30 percentage points compared to last year.

Previously, workers manually set up the rolling schedule, which could lead to human error. With AI-based schedule automation, such errors can be prevented, and productivity and energy cost savings are expected to be achieved.

According to Gwangyang Steelworks, since the introduction of this system in January this year, about 10 billion KRW in energy costs have been saved by August.

The development of this system set a precedent for interdepartmental collaboration, as it was achieved through the organic cooperation of various departments at Gwangyang Steelworks. The Sales and Production Coordination Office consolidated orders from clients and adjusted the production schedule in advance, taking the production site into account, which greatly assisted the Production Technology Department in optimizing the schedule.

The Steelmaking Department focused on improving caster equipment to prevent the casting of defective slabs. If hot slabs with excessive impurities are cast, a separate refining process is required, so a scarfing (impurity removal) process must be conducted before heating. This process requires lowering the temperature, which results in the slab being converted to a cold slab. To prevent such situations, the Steelmaking Department has been working to improve the caster equipment itself to avoid the production of defective slabs.

Jung Daehyun, Head of the Production Technology Department at Gwangyang Steelworks, said, "Through collaboration among various departments, we have laid the technological foundation for expanding energy-saving hot rolling operation systems," adding, "We will make every effort to secure the competitiveness of Gwangyang Steelworks by actively expanding the application of scheduling automation technology."