Abstract: Disclosed is an austenitic welding material which contains C: 0.01 wt % or less, Si: 0.5 wt % or less, Mn: 0.5 wt % or less, P: 0.005 wt % or less, S: 0.005 wt % or less, Ni: 15 to 40 wt %, Cr: 20 to 30 wt %, N: 0.01 wt % or less, O: 0.01 wt % or less, and the balance of Fe and inevitable impurities, wherein the content of B contained as one of the inevitable impurities in the welding material is 3 wt ppm or less, and the total content of C, P, S, N and O in the welding material is 0.02 wt % or less.

Abstract: Disclosed is an austenitic welding material which contains C: 0.01 wt % or less, Si: 0.5 wt % or less, Mn: 0.5 wt % or less, P: 0.005 wt % or less, S: 0.005 wt % or less, Ni: 15 to 40 wt %, Cr: 20 to 30 wt %, N: 0.01 wt % or less, 0: 0.01 wt % or less, and the balance of Fe and inevitable impurities, wherein the content of B contained as one of the inevitable impurities in the welding material is 3 wt ppm or less, and the total content of C, P, S, N and O in the welding material is 0.02 wt % or less.

Abstract: An austenitic stainless steel excellent in intergranular corrosion resistance and stress corrosion cracking resistance, comprising: C: 0.005 wt % or less; Si: 0.5 wt % or less; Mn: 0.5 wt % or less; P: 0.005 wt % or less; S: 0.005 wt % or less; Ni: 15.0 to 40.0 wt %, Cr: 20.0 to 30.0 wt %, N: 0.01 wt % or less; O: 0.01 wt % or less; and the balance of Fe and inevitable impurities, wherein the content of B included in the inevitable impurities is 3 wt ppm or less.

Abstract: A Si—SiC material of Si concentration-gradient type is obtained by melt-infiltrating Si into a molded material comprising SiC particles. The Si—SiC material has a porosity of 1.0% or less and in the Si—SiC material the Si concentration decreases gradually from the surface layer towards the innermost layer. A SiC fiber-reinforced Si—SiC composite material of Si concentration-gradient type is obtained by melt-infiltrating Si into a molded material comprising a SiC fiber and SiC particles. The composite material has a porosity of 1.0% or less and in the composite material the Si concentration decreases gradually from the surface layer towards the innermost layer. These materials are significantly improved in corrosion resistance in highly oxidative and corrosive environment, strength, and healability of defects of surface layer and innermost layer.

Abstract: A Si—SiC material of Si concentration-gradient type is obtained by melt-infiltrating Si into a molded material comprising SiC particles. The Si—SiC material has a porosity of 1.0% or less and in the Si—SiC material the Si concentration decreases gradually from the surface layer towards the innermost layer. A SiC fiber-reinforced Si—SiC composite material of Si concentration-gradient type is obtained by melt-infiltrating Si into a molded material comprising a SiC fiber and SiC particles. The composite material has a porosity of 1.0% or less and in the composite material the Si concentration decreases gradually from the surface layer towards the innermost layer. These materials are significantly improved in corrosion resistance in highly oxidative and corrosive environment, strength, and healability of defects of surface layer and innermost layer.

Abstract: A Si—SiC material of Si concentration-gradient type is obtained by melt-infiltrating Si into a molded material comprising SiC particles. The Si—SiC material has a porosity of 1.0% or less and in the Si—SiC material the Si concentration decreases gradually from the surface layer towards the innermost layer. A SiC fiber-reinforced Si—SiC composite material of Si concentration-gradient type is obtained by melt-infiltrating Si into a molded material comprising a SiC fiber and SiC particles. The composite material has a porosity of 1.0% or less and in the composite material the Si concentration decreases gradually from the surface layer towards the innermost layer. These materials are significantly improved in corrosion resistance in highly oxidative and corrosive environment, strength, and healability of defects of surface layer and innermost layer.