NIMS Creep Data Sheet Project Was Registered as MIRAI Technology Heritage

"① Documents by the Creep Committee of the Iron and Steel Institute of Japan", "② Creep machines and their design drawings and blueprints", as well as "③ Creep data sheets, test records, and creep-ruptured specimens" were registered as 2024 essential historical materials for science and technology by the National Museum of Nature and Science.

From left, ① Minutes of the first Creep Committee, ② Design drawings of creep machines,
and ③ Creep-ruptured specimens

① Documents by the Creep Committee of the Iron and Steel Institute of Japan

These documents are the foundation of the plan for long-term creep tests in the NIMS Creep Data Sheet Project. In 1964, a recommendation for the development of supercritical pressure power generation was issued by the Science and Technology Agency Resources Council. The recommendation stated that it was necessary to develop new heat-resistant steels for power generation. The Creep Committee was established by the Iron and Steel Institute of Japan to obtain long-term creep data because available data regarding domestic heat-resistant materials were insufficient. The Creep Data Sheet creation methodology plan was approved by the Creep Committee, a partnership straddling industry, the government, and academia.

② Creep machines, their design drawings, and blueprints

These technologies have supported long-term creep tests for more than several decades. Creep machines were designed by the National Research Institute for Metals in the 1960s. The design drawings of the creep machines are preserved in the NIMS. The body frames of the creep machines are used in their original forms. However, the electric furnaces and temperature regulators have been replaced by the latest equipment. These technologies are supporting long-term creep tests, such as the world’s longest creep testing over 40 years.

③ Creep data sheets, test records, and creep-ruptured specimens

These materials are records to ensure the quality of long-term creep data. The long-term creep data have been published as NIMS creep data sheets since 1966. NIMS creep data sheets are widely used in industries as reference data for allowable stress and materials selection in high-temperature components. Records of dimensional measurements of creep specimens, identification numbers of thermocouple and events such as power cuts and earthquakes during long-term creep tests are preserved for each creep test. About 12,000 creep-ruptured specimens are identifiable and used for microstructure observation to understand material degradation.

On September 10, 2024, the registration certificate ceremony for MIRAI Technology Heritage was held at the National Museum of Nature and Science, and certificates of registration were handed over to NIMS President Kazuhiro Hono, Specially Appointed Researcher Kazuhiro Kimura, and Group Leader Kota Sawada by the museum director Kenichi Shinoda.

What is the Creep Test?

The test to measure the amount of creep deformation and rupture of metal materials over a long time, in the atmosphere of where constant loads suspend from test pieces heated to high temperatures.
When metal materials suffer from loads at high temperatures, a phenomenon called "creep", meaning crawl, occurs and plastic deformation gradually progress over time.
Therefore the creep test is crucial for metal material innovation for those used in large high-temperature equipments such as boilers, turbines in thermal power generation plants, and pressure vessels in petrochemical plants.