Effect of prestrain on cyclic creep behaviour of a high strength spring steel

Ratchetting behavior of advanced 9–12% chromium ferrite steel under creep-fatigue loadings

“…It is worth noting that the peak value of back stress (or valley value of effective stress) at the end of stage I ⁄ is close to the initial level observed in the L-HT domain. According to previous studies (Yang and Wang, 1996;Gaudin and Feaugas, 2004;Sasaki et al, 2007), predeformation had a great influence on the ratchetting deformation. Those results suggested that the ratchetting behavior in the subsequent cyclic loading was related to dislocation structure developed in plastic strain history (pre-deformation).…”

“…However, most of the existing studies have focused on developing the phenomenological descriptions. Only a few works have been reported concerning physical arguments on the origin and the mechanism of ratchetting (Lorenzo and Laird, 1984a,b;Chandler and Bee, 1985;Yang and Wang, 1996;Melisova et al, 1999;Feaugas and Gaudin, 2004;Gaudin and Feaugas, 2004). According to those studies, besides peak stress and mean stress, pre-loading shows a large influence on the ratchetting deformation.…”

Fatigue of OFHC pure copper and 316L stainless steel subjected to prior tensile and cyclic prestrains

“…Moreover, this difference of stress level, henceforth called "memory effect", is not the only parameter affected by a prestrain and modifications of other mechanical properties were also reported (e.g. cyclic stress-strain response and fatigue life [4][5][6][7][8][9][10][11][12][13][14][15], creep and ratcheting tendencies [14,[16][17][18][19][20] and fracture toughness [21]). Memory effect is thus of an overall importance for metallic materials.…”

Effect of Al deoxidizing for Spring steel during LF Process

“…The cleanness of the spring steel has a very important influence on the service life of the spring [1]. So, it has a remarkable effect on improving the fatigue resistance ability that reduces the oxygen content and the non-metallic inclusions, and improves the shape and distribution of the inclusions, especially, the big grain, high melting point brittle inclusions such as alumina and aluminate, and pointed titanium nitride inclusions which is the main causation that causes the breakage of the spring [2].…”