HAEDENED BY OVERSTRAIN. 
7 
Diagram No. 2. (Annealed Steel.) 
Extensions— diminished as explained on page 4- 
Scale-.—1 Unit = of an inrh ? 1 
Curve No. 1—Primary test. 
,, „ 2—Shortly after No. 1. 
j) ^ f'j days ,, ,, 1. 
„ „ 4—2 weeks „ „ 1. 
5—After heating 
to about 
300'’ C, 
6— „ 
n 
300'’ C, 
300° C. 
8— 
300° C. 
The Effect of Annealing. 
It was found that the process of annealing altered in an interesting fashion the 
elastic properties of the material whose virgin properties are illustrated in Diagram 
No. 1. The primary yield-point was found to he considerably lowered by annealing, 
and the step by wdiich the yield-point was raised in consequence of overstrain and 
