Patent ID: 9073114
Filing Date: 2015-07-07
Classification: B22D,C21D,C22C

Abstract:
1. An enameling steel sheet excellent in fishscale resistance comprising a chemical composition consisting of, in mass %, C: 0.0003% to 0.010%, Si: 0.001% to 0.100%, Mn: 0.03% to 1.30%, Al: 0.0002% to 0.010%, N: 0.0055% or less, P: 0.035% or less, S: 0.08% or less, O: 0.005% to 0.085%, Nb: 0.113% to 0.250%, optionally B: 0.0003 to 0.0030%, optionally V: 0.003 to 0.15%, optionally Ti: 0.0001 to 0.05%, optionally Cr: 0.0001 to 0.05%, optionally one or more of Ta, W, La, Ce, Ca or Mg in a total of 1.0% or less, optionally one or more of As, Se, Sn or Sb in a total of 1.0% or less, and a balance of Fe and unavoidable impurities, wherein the enameling steel sheet further comprises: a first Fe—Nb—Mn system composite oxide, selected from the enameling steel sheet at random, the first Fe—Nb—Mn system composite oxide having internal variation of Nb mass % concentrations, wherein the Nb mass % concentration of a high-concentration region, Nb max %, of the first Fe—Nb—Mn system composite oxide is higher than the Nb mass % concentration of a low-concentration region, Nb min %, of the first Fe—Nb—Mn system composite oxide, and a ratio of Nb max %/Nb min %≧1.2.