| 摘要 |
PURPOSE:To produce a shadow mask original plate which has the smaller intra-surface anisotropy of the coefft. of elasticity by specifying the cold rolling draft of the cold rolling just before the final recrystallization annealing at the time of repeatedly subjecting the hot rolled sheet of an Fe-Ni 'Imvar(R)' alloy having a low coefft. of thermal expansion to the cold rolling and the recrystallization annealing. CONSTITUTION:The hot rolled material of the Fe-Ni 'Imvar(R)' alloy having the low coefft. of thermal expansion is repeatedly subjected to >=2 passes of the combination of the cold rolling stage and the recrystallization annealing stage and the final stage is executed by a hardness imparting cold rolling stage to produce the shadow mask material. The cold rolling just before the final recrystallization annealing stage is executed at 40-80% cold rolling draft and the final cold rolling to impart the hardness is executed at about <=40% draft. The content of Ni in the Fe-Ni 'Imvar(R)' alloy is specified to 34-38wt.% and part of Ni can be substd. with Co up to 1-10wt.%. The contents of Cr, Mo, Nb, Ti, Zr, Ta, Cu, and W which are additive elements are respectively <=2%. The shadow mask original plate which allows the formation of the fine holes to be passed with electron beams with high accuracy and high density is thereby obtd. |
