- Fe-Ni ALLOY FOR SHADOW MASK HAVING EXCELLENT PROPERTIES IN ETCHING WORKABILITY METHOD FOR OBSERVING INCLUSIONS AND METHOD FOR DETERMINING THE UNIFORMITY OF HOLES

摘要

The present invention provides a material for a shadow mask which is excellent in etching punching property without deviation of electron beam transmission pore diameter during etching processing.;The present invention relates to a steel sheet comprising 34 to 38% of Ni and 0.5% or less of Mn and having a balance of Fe and inevitable impurities or accompanying elements, wherein C is not more than 0.10%, Si is not more than 0.30%, Al is not more than 0.30% 0.005% or less, and P: 0.005% or less. When the surface of the material is immersed in a 3% nitric acid-ethyl alcohol solution at 20C for 30 seconds after mirror polishing, the diameter of the Fe-and an etching hole having a diameter of 10 to 20 m and a diameter of 10 to 20 m, and an etching hole having a diameter of 10 m to 10 m. The present invention also provides a simple observation method for the presence of minute inclusions or precipitates in the Fe-Ni based alloy material and a method for discriminating the hole diameter uniformity when the electron beam penetrating hole is drilled by etching.