SMS group
The 90/108-MN open-die forging press designed by SMS and now operating at Hitachi Metals Ltd.’s Yasugi Works.

New Open-Die Design for Power and Precision

June 1, 2019
SMS describes 90/108-MN machine at Hitachi Metals as the largest four-column, push-down design press it has built in over two decades.

An open-die forging press for temperature-sensitive metals started up recently at Hitachi Metals Ltd.’s Yasugi Works in Japan is reported to be the largest four-column, push-down press designed and built by SMS in the past 25 years.

Hitachi Metals issued its final acceptance certificate for the design and installation program earlier this year, following a commissioning sequence.

Hitachi Metals is one of a dozen current operating units of Hitachi Ltd., manufacturing specialty steel and alloy products, components, and various products related to such materials for automotive, infrastructure, and electronics markets. The Yasugi Works melts and casts specialty steels into ingots, which are forged and/or rolled to semi-finished products, including blooms, billets, and slabs.

The forging capabilities there include closed-die forging for net-shape components and high-speed forge-rolling for long products.

The new machine is designed to deliver a forging force of 90 MN (9,177.4 mt-force) and an upsetting force of 108 MN (11,012.9 mt-force.) Hitachi Metals is using the open-die press to forge flat and round bars from ingots up to 30 mt, in temperature-sensitive materials like titanium alloys, tool steels, high-speed steels, and nickel-based alloys.

Two rail-bound manipulators position the workpieces with “millimeter precision,” according to the press developer, and move them in full synchronization with the press stroke.

SMS described a high-efficiency, space-saving hydraulic system concept involving 18 high-performance hydraulic pumps installed in the four-column, push-down press. A twin-pump arrangement (two pumps operated by one motor) means the hydraulic system requires significantly less space than otherwise would be necessary.

In response to Hitachi Metals’ request for fast-tool change capability on the press, SMS group developed a tool-changing system by which only the die track needs to be replaced. The entire tool changing process is performed fully automatically. The scope of supply for the press also included a table-shifting device, a die-shifting device, and a die magazine.

Another technical feature is a three-dimensional laser measuring system that determines the surface temperature and the geometry of the forging in real time, and optimizes pass schedules for homogeneous forging of the core zone.

Hitachi also adopted the SMS ForgeBase® control software for optimized, reproducible forging results. The program supplies pass schedules for the forging process based on extensive material databases. The software’s open-loop and closed-loop control circuits ensure precise coordination of the manipulator movements and press strokes. The part models supplied by the software and based on predetermined pass schedules ensure that production sequences are both precise and cost-efficient.

ForgeBase also allows press operators to switch from fully automatic to semi-automatic or manual operating modes, as required.

The press was built on a vibration-isolating foundation consisting of an intermediate footing and several vibration dampers. Residual vibration measured at a reference point meets Hitachi Metals’ specifications, and the horizontal stoppers installed on the sides give extra stability — in case of earthquakes, the developer noted.