SEHAVIOUR OF MATERIALS IN TESTING MACHINE 181 
Tenacity and Elongation of Steel after Heat Treatment. 
_ [cation percent. . | 0-130 | 0180 | 0:254 | 0-468 | 0-722 |o-871 | 0-947 | 1-306 
Bars as received from the rolls. 
_ | Maximum stress at 22 | 31°52 | 33-25 em 49-00 | 58-02 | 53°74 | 56°11 
20°00 12°50 | 12°70] 6°25*| 11:72) 5:47) 7:03] 7°03 
Bars annealed at 720° C. for half-an-hour. 
20°16 | 26°52 | 28°80 | 32°82 | 39°96 | 43°98 | 39°30 | 50°58 
44°50 | 36°00 | 32°50 | 29-00 | 23-00 | 20-00 | 22° 7 
_ | Maximum stress 
Elongation 
Bars annealed at 1100° C. for half-an-hour. 
Maximum stress 26-91 28°11 | 31°38 | 42°38 | 47-69 | 49°62 | 46°62 
| Elongation 39°50 | 33°50 | 27-00 | 14:00 |} 11:00 7° 50 | 6°50 
Bars soaked at 620° C. for twelve hours. 
Maximum stress 19°75 | 26°81 | 28°61 | 32°01 | 40°63 | 45°25 | 45-41 | 46°96 
Elongation 48°50 | 32°50 | 31-00 | 33°00 | 29°50 | 19°50 | 18-50 | 11:50 
Bars soaked at 900° C. for twelve hours. 
i Maximum stress F «-» | 26°91 | 29°55 | 29°91 | 43°21 | 49°32 | 47-76 | 44-41 
| Elongation . .| ... | 87:00! 29:00/| 30:00| 12-50 | 11:00] 11-90 | 10-00 
Bars quenched at 900° C. in Water at 20° C. 
_| Maximum stress . | 82°34 | 49°92 | 70°32 | 55°44 | 61-98 | 26-04 | 21°60 
| Elongation . .| 28-20] 6:50| 3:80| 1:00] 1-00] 2:00] nil. 
48 Bars quenched at 1200° C. in Water at 20° C. 
: Maximum stress - | 45°29 | 72°78 | 77°04 | 31:74 | 13°44] 5:40] 4:20] 3-52 
| Elongation -| 900) 3°50) 3:00} nil. | nil. | nil. | nil. | nil. 
2 _ Bars quenched at 870° C. in Oil at 80° C., and subsequently reheated to 350° C. 
. 
z Maximum stress - | 24°50 | 36°12 | 41°13 | 54°65 | 78°59 | 90°68 ae! . pe 
? os ancaaimaa : - | 89°50 | 23°50 | 24°50 | 25-00 | 23-50 | 10°50 
Bars quenched at 900° C. in Oil at 80° C., and subsequently reheated to 600° C. 
| Maximum stress 24°55 | 30°13 | 31-24 | 35-71 | 50°44 
ion 40°70 | 30-00 | 26-20 | 27-20 | 17-50 
52°68 | 49°10 | 51°32 
15°50 | 17°00 | 13:00 
* Abnormal result, 
