HIGHLY PURE METALLIC CHROME ROLLED BODY AND ITS MANUFACTURING METHOD

摘要

PURPOSE:To obtain a rolled body of chrome metal having a specific elongation percentage by cross rolling a chrome metal lump at a temp. in a specific temp. range and then warm rolling the lump. CONSTITUTION:A chrome metal lump of a purity of >=99.9% is cross rolled at a temp. in the range of 300 to 700 deg.C near to the ductility-brittleness transition temp. as the initial rolling at an ultraslow speed of 0.05-1m/min. Then, the lump is made to a rolled body having an elongation of >=10% in a tensile test at room temp. by warm rolling. The metal structure is controlled and structural orientation of the rolled body is eliminated by the cross rolling, so that the chrome metal rolled body having a prescribed thickness without cracks is obtained. Elongation percentages in the above time are 1-5%/rolling. An elongation percentage of <1% can not control the metal structure and cracks are generated by elongation percentages of >5%.