Kobe Steel Develops Extra High Purity Austenitic Stainless Alloy

Kobe Steel announced on Thursday the firm developed the world first production method for Extra High Purity (EHP) austenitic stainless steel alloy in cooperation with Japan Atomic Energy Agency (JAEA). The new alloy will contribute to longer lives and higher performances of complex energy equipment such as ultra-high burnup furnaces or hydrogen energy facilities. Kobe Steel tries to start the commercial production of this new alloy and expects the annual sales at several hundred million yen after 5 years.

The newly developed technology is a mixture of the reducing refining method and the volatilizing refining method. The new production technology realizes equal alloy composition if using cheap materials and large-lot output of extra high purity alloy ingot with impurities, such as carbon, phosphorus, sulfur or nitrogen, at less than 100 ppm. With few impurities, austenitic stainless steel alloy represents its high performances including corrosion resistance, irradiation resistance and mechanical characteristics.

Kobe Steel and JAEA expect EHP austenitic stainless steel alloy could become a substitutable material for SUS310 or Cr25-Ni35 alloy especially in environment and energy related fields. EHP austenitic stainless steel alloy decreases risks of radiation aging, local corrosion and crack occurrence, that is, the alloy contributes to longer lives of evaporators in reprocessing facilities and core support structures in nuclear power reactors. The new alloy is also able to be welded by a welding material of the same alloy.