Abstract:

The fatigue life gage resistance accumulation will be partly recovered when it is annealed. The experiment result reveals that the resistance change caused by dislocation and point defect will be reserved when it is annealed below temperature of recrystallization, while the resistance change caused by alloy element order in lattice disappeared. Its mechanism of resistance accumulation studied using annealing technique on three alternating strain levels after fatiguing. Its character after treatment in nitrogen and cold work also researched. The experiment results indicated that most resistance accumulation disappeared for low cyclic fatigue after being annealed in temperature about 450℃, and relatively more resistance accumulation was reserved for high cyclic fatigue annealed in this temperature. This shows that the resistance increase due to dislocation and point defect is the main factor, and the prime contribution to resistance increase of fatigue life gage is due to the change of alloy element order in lattice. The resistance is increased in reversed strain after cold work and its character has no distinct change when it keeps in low temperature.

Key words: fat igue life, cyclic str ain, resistors, annealing