CHROMIUM-ZIRCONIUM COPPER ALLOY FORGED PLATE MATERIAL AND METHOD FOR MANUFACTURING THE SAME

To provide a method for manufacturing a CuCrZr alloy forged plate material which can suppress abnormal growth of crystal grains generated by heating at approximately 900°C without addition of a new element.SOLUTION: A method for manufacturing a chromium zirconium copper alloy forged plate material for a member used for neutron beam irradiation environment includes: a first forging step of hot upsetting and forging a Cu alloy ingot containing 0.9-2.0 mass% of Cr and 0.02-0.20 mass% of Zr at a temperature at least 800°C; a second forging step of roughly working the ingot into a plate material; and a machine working step of cutting and facing the plate material so that conductivity is 64% IASS or more and its fluctuation range Δσ becomes 5% or less, and provides a forged plate material having an average crystal particle diameter in a longitudinal section and a transverse section even when air cooling the plate material after heating the plate material at 980°C or higher for 2 hours of 100 micrometer or less. In the manufacture method, the plate material preferably has a metallic structure such that Cr spherical particles with an average particle diameter of 5 μm or less are dispersed. The production method includes aging treatment of holding the plate material at 400-600°C.SELECTED DRAWING: Figure 1 【課題】新たな元素を添加せずに９００℃程度の加熱で生じる結晶粒異常成長を抑制できるＣｕＣｒＺｒ合金鍛造板材の製造方法の提供。【解決手段】中性子線照射環境下で使用される部材用のクロムジルコニウム銅合金鍛造板材の製造方法であって、Ｃｒを０．９〜２．０質量％、Ｚｒを０．０２〜０．２０質量％とするＣｕ合金塊を８００℃を下回らない温度で据え込み鍛造する第１鍛造工程と、板材に粗加工する第２鍛造工程と、導電率を６４％ＩＡＣＳ以上でその変動幅Δσを５％以下とする様に切断及び面削する機械加工工程と、を含み、９８０℃以上で２時間の加熱後空冷しても縦断面及び横断面での平均結晶粒径を１００マイクロメータ以下とする鍛造板材を与えるＣｕＣｒＺｒ合金鍛造板材の製造方法。好ましくは平均粒径で５μｍ以下のＣｒ球状粒子を分散させた金属組織を有する、製造方法。４００〜６００℃で保持する時効処理を含む、製造方法。【選択図】図１