The durability of a first part submitted to fatigue during the service is a very important parameter in the safety of a mechanic structure’s functioning. This thing is necessary both the environmental temperature and to low temperatures. For a stainless steel, mark 10 TiNiCr 175 fatigue attempts were made through eccentric straightening, with the asymmetry coefficient R=0.5, on the temperatures T=293 K, T=253 K and T=213 K. For the low temperatures (253 K and 213 K) we mounted on the attempt machine a frigorific chamber cooled with liquid nitrogen. During the attempt we have kept in mind the variation of the crack’s length ai and the durability Ni. The samples tested had type CT, with lateral notch. We calculated according to the ASTM norm the stress intensity factor ?K at the top of the crack. The fracture is produced after the mode I of solicitation, by opening the crack. Through a numeric calculation program we have then calculated and then drawn graphics for the durability N in report to the calculated length a, respectively in report to stress intensity factor N(?K).
