Tokyo, June 30, 2003 - JFE Steel Corporation announced today that the company had completed installation of a Super-OLAC (On-Line Accelerated Cooling) system at the Kurashiki plate mill operated under its West Japan Works in early April. After passing a series of quality checks, the system began full-scale operation in May, and the line has already started manufacturing and shipping steel plate primarily to the shipbuilding industry.

The startup of the new system will enable JFE Steel to more efficiently produce high-quality steel plate with superior strength, excellent toughness and improved weldability, meeting diversified customer demand.

Super-OLAC uses an accelerated water-cooling device to cool and quench hot-rolled steel plate online immediately after hot rolling, thereby upgrading plate toughness.

In conventional methods, the impact between the hot steel plate and the cooling water produces a partial steam film that results in uneven and inefficient cooling.

Super-OLAC improves the impact flow and pressure to eliminate the steam film from the steel surface and produce the nucleate boiling that is considered to be the ideal form of cooling. Nucleate boiling enables direct contact between the steel and cooling water for maximally efficient heat transfer (See Figure). The result is a rapid cooling rate that is close to the theoretical limit, successfully combined with more precise control over the cooling finishing temperature. Super-OLAC achieves more uniform cooling throughout the plate than that of conventional processes. The use of Super-OLAC also imbues low-alloy steel plate with high strength and toughness, which improves weldability and seismic resistance. This marks a significant advance in the creation of more environment-friendly steel products.

The first Super-OLAC system was installed in September 1998 at the former NKK Fukuyama Works plate mill (now the Fukuyama plate mill operated under West Japan Works). The technology has subsequently been applied to shape steel and hot strip mills. NKK was awarded the Okochi Memorial Prize for Technology for Super-OLAC in 2002.

The new system at Kurashiki is based on the Super-OLAC system at Fukuyama but incorporates various improvements to handle plate width up to 5,350mm (compared to 4,400mm at Fukuyama) and applies the technology to different forms of LP (longitudinally profiled) plate (taper plate). JFE Steel was formed on April l this year following the merger of NKK and Kawasaki Steel last September. Even prior to consolidation, however, there was significant technology exchange between the firms further reinforced with personnel exchange after consolidation. This cooperation enabled the company to quickly install the new system at the Kurashiki plate mill, and move immediately to commercial production.

Super-OLAC is part of the JFE Steel strategy to develop advanced "only one" and "number one" products and technologies that meet changing customer needs.

Super-OLAC at Kurashiki plate mill operated under
JFE Steel West Japan Works