Abstract: A high-nitrogen ferritic heat-resisting steel with high vanadium content comprises, in weight percent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.005-1.00% Mo, 0.20-1.50% W, 0.30-2.00% V, and 0.10-0.50% N and being controlled to include less than 0.020% Nb, the balance being Fe and unavoidable impurities. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the resulting melt in an atmosphere controlled to have a total pressure of not less than 2.77 bar and a nitrogen partial pressure of not less than 1.0 bar, with the relationship between the nitrogen partial pressure p and the total pressure P beingP>2.77pthereby obtaining sound ingot free of blowholes.

Abstract: The strains in crystals are evaluated by quantifying the sharpness of an electron channeling pattern and determining changes in the quantified sharpness of the electron channeling pattern. There is such a close correlation between the sharpness of the electron channeling pattern and the strains in crystals that the latter can be evaluated in terms of changes in the former. An apparatus for evaluating strains in crystals comprises a scanning electron microscope having a function to form an electron channeling pattern and an image analyzer having a function to quantify the sharpness of an electron channeling pattern.