A martensitic stainless steel for a disc brake rotor includes, in mass percent, C: 0.04-0.10%, Si: at most 1.0%, Mn: 0.1-2.0%, P: at most 0.04%, S: at most 0.01%, Cr: greater than 11.5 to 13.5%, Al: at most 0.1%, N: at most 0.04%, Cu: 0-1.0%, Ni: 0-1.0%, Ti: 0-0.03% and one or more of Nb: 0.01-0.08% and V: 0.05-0.5%, with the value of GP expressed by the following formula being at least 50 (%): ##EQU1##

Martensitic нержавеющая сталь для ротора тормоза диска вклюает, в массовые проценты, ч: 0.04-0.10%, кремний: на большой части 1.0%, маргаец: 0.1-2.0%, п: на большой части 0.04%, с: на большой части 0.01%, cr: greater than от 11.5 до 13.5%, al: на большой части 0.1%, н: на большой части 0.04%, cu: 0-1.0%, ni: 0-1.0%, ti: 0-0.03% и one or more из N B: 0.01-0.08% и в: 0.05-0.5%, при значение gp выраженное following формулой по крайней мере 50 (%): ## ## EQU1