Stainless steel brake disc and method for production thereof

摘要

The present invention is directed to a stainless steel brake disc which is excellent in toughness, corrosion resistance, and wear resistance, and comprises, in % by mass, 0.030 to 0.080% of C, 0.05% to 1.0% of Si, 1.0 to 1.5% of Mn, 0.035% or less of P, 0.015% or less of S, 11.0 to 14.0% of Cr, 0.01 to 0.50% of Ni, 0.001 to 0.15% of V, less than 0.1% of Nb, 0.05% or less of Ti, 0.05% or less of Zr, 0.05% or less of Al, 0.015 to 0.060% of N, 0.0002% or more and 0.0050% or less of B, and 0.0080% or less of O, wherein an AT value of equation 1 is 0.055 to 0.090, equation 2 is satisfied, a ferrite phase fraction, in which an IQ value of an EBSD pattern is 4,000 or more, is 1% to 15%, a Charpy impact value is 50 J/cm2 or more, and hardness is 32 to 38 HRC.
C+0.8(N−B)  (1)PV=1.2Ti+0.8Zr+Nb+1.1Al+O≦0.1  (2)

主权项

1. A stainless steel brake disc comprising, in % by mass, a stainless steel comprising 0.030 to 0.080% of C, 0.05% to 1.0% of Si, 1.0 to 1.5% of Mn, 0.035% or less of P, 0.015% or less of S, 11.0 to 14.0% of Cr, 0.01 to 0.50% of Ni, 0.001 to 0.15% of V, 0.10% or less of Nb, 0.05% or less of Ti, 0.05% or less of Zr, 0.05% or less of Al, 0.015 to 0.060% of N, 0.0002% or more and 0.0050% or less of B, and 0.0080% or less of O,
wherein an AT value of equation 1 is 0.055 or more and 0.090 or less, equation 2 is satisfied, the balance of the stainless steel is Fe and inevitable impurities, a ferrite phase fraction of the stainless steel, defined by the fact that an image quality value of an electron backscatter diffraction (EBSD) pattern is 4,000 or more, and said ferrite phase fraction is 1% or more and 15% or less of the stainless steel, and surface hardness of the stainless steel is 32 HRC or more and 38 HRC or less:
AT=C+0.8(N−B)  (1)PV=1.2Ti+0.8Zr+Nb+1.1Al+O≦0.1  (2)where N, B, Ti, Zr, Nb, Al, and O in equation 1 and equation 2 each means the element content (% by mass).