Sumitomo Metals Receives World’s First Order for H-SA700, Innovative Ultra-high Tensile Strength Steel
- Realizing Safe Wide Span Space That Withstands Large Earthquakes -

1. Orders for H-SA700
Sumitomo Metal Industries, Ltd. (Sumitomo Metals) has received the world’s first order for its innovative ultra-high tensile strength steel, H-SA700, from Obayashi Corporation (Obayashi) for construction of a “Techno Station” main building at its Technical Research Institute. H-SA 700 is a ultra-high tensile strength steel material which has yield strength that is about twice as high as conventional steel. It was developed to improve the seismic performance of buildings in the project (*1) concerning “Research & development of buildings with new structural systems that use innovative structural materials.” In addition, Sumitomo Metals has independently developed a process innovation for this material. Specifically, the preheating for the welding work can be omitted.

A steel stand column made of H-SA700, when filled with ultra-high strength concrete developed by Obayashi, becomes an ultra-high strength CFT column. This column makes the building safe even against a major earthquake and allows the creation of a large space with a wide span between the columns, which is excellent in terms of design and amenity, as columns made of this material can be thinner and buildings require the installation of fewer columns.

2. Line-up of ultra-high tensile steel building materials
Sumitomo Metals has developed and received the approval of the Minister of Land, Infrastructure and Transport for the following ultra-high strength steel building materials including H-SA700. These materials are adopted in commercial use. (*3)

(2) Renewal of Sumitomo Metals’ Corporate Research & Development Laboratories
Sumitomo Metals is constructing new research buildings of its Corporate Research & Development Laboratories at Amagasaki city. The first floor of the new laboratory has the dampers: a structure that enables columns to sway flexibly and seismic energy to be absorbed by dampers, when there is an earthquake. The pillars of the buildings must have high yield strength to support weight load of the upper floors, without causing any damage or deformation. On the first floor of the new laboratory, SSS1000, material with the world’s highest strength, is being applied for the first time. This material was jointly developed by Sumitomo Metals, Osaka University, the Kyoto Institute of Technology, Nikken Sekkei Ltd., and Katayama Stratech Corp.

Against this background, the project was intended to review designs and materials for buildings, so that they could be used even after a large earthquake. In terms of design, dampers are to be designed to allow the absorption of seismic energy. In terms of materials, ultra-high strength steel materials are to be used so that pillars and beams are not deformed but return to their original shape. H-SA700 is a material manufactured with a reduced amount of alloying elements and by omission of heat treatment. It was developed to achieve economic performance and higher strength. As a member of the Japan Iron and Steel Foundation, Sumitomo Metals was involved in the development of H-SA700.