Stainless steel foil for flexible display use
View Patent ↗The present invention provides stainless steel foil for flexible display use which enables fabrication of a TFT substrate for display use which is superior in shape recovery after being rolled up or bent and which is high in surface flatness and is characterized by having a thickness of 20 μm to 200 μm, a surface roughness Ra of 50 nm or less, and a shape recovery of a distortion angle of 10° or less after being wound around a 30 mm diameter cylinder.
1. A ferritic stainless steel foil for flexible display use comprising, in mass %:
C≦0.015%,
Si≦0.50%,
Mn≦0.50%,
P≦0.04%,
S≦0.03%,
Cr: 18.00 to 20.0%,
Mo: 1.75 to 2.25%,
N≦0.011%,
Ti+Nb≧16(C+N),
with the balance Fe and unavoidable impurities,
having a thickness of 20 μm to 200 μm,
a surface roughness Ra of 50 nm or less obtained by superbright finishing without bright annealing,
a 0.2% yield strength of at least 600 N/mm 2 , and
a shape recovery distortion angle of 10° or less after being wound around a 30 mm diameter cylinder.