Effect of Assembly Stresses on Fatigue Life of Symmetrical 65Si7 Leaf Springs

Table 8

Experimental fatigue life of the specimens under different stress ranges.

Material processing	Standard specified	Alternating stress level (MPa)	Stress range	Fatigue life of 𝑆-1; (𝑁𝑓)	Fatigue life of 𝑆-2; (𝑁𝑓)	Fatigue life of 𝑆-3; (𝑁𝑓)	Fatigue life of 𝑆-4; (𝑁𝑓)	Average SD
Normal rolling, quenching at 880°C, tempering at 410°C for 90 mins, shot peening at 18 A intensity, BHN 380–432, and scragging at 0.9% of yield stress	0.6 g–2 g; (As specified)	269–896	627	84212	81961	82226	85656	Avg. 83513; SD 1518
Normal rolling, quenching at 880°C, tempering at 410°C for 90 mins, shot peening at 18 A intensity, BHN 380–432, and scragging at 0.9% of yield stress	(Without 𝑆𝑎)	218–969	751	66796	69320	70119	69956	Avg. 69047; SD 1333
Normal rolling, quenching at 880°C, tempering at 410°C for 90 mins, shot peening at 18 A intensity, BHN 380–432, and scragging at 0.9% of yield stress	(With 𝑆𝑎)	200–885	685	74827	76658	79010	77229	Avg. 76931; SD 1492