REPORT ON VARIABLE TENSILE PROPERTIES OF 1015 STEEL AT 16000 TO 2000"F By R. Jackowski J. W. Freeman PROJECT 842 REPORT 202 May24, 1954 THE TIMKEN ROLLER BEARING COMPANY STEEL AND TUBE DIVISION CANTON, OHIO

INTRODUCTION Very wide variations in ductility were obtained in this investigation between heats of 1015 steel in the temperature range between 1600~ and 2000~F. At present, the reasons for the variations are not apparent. A very striking effect is shown, however, which should be important in the processing and fabrication of such steels. Rather low ductilities in particular ought to cause difficulties in brazing, welding, and, possibly, hot-working operations. SUMMARY Of eight heats of 1015 steel subjected to tensile tests at tempera. ture from from 1600~ to 2000~F, four gave elongations ranging between 65 and 82 percent. For the other four, the range was from 13 to 39 percent, with a minimum between 1700~ and 1800~F of 13 to 21 percent. Similar variation in reduction of area occurred. The range in tensile strengths was small, although the more ductile heats tended to have lower tensile strengths. There was no apparent relationship between reported variations in chemical analysis and the ductility characteristics.

2 TEST MATERIALS Tensile specimens, 0. 505 inches in diameter, were supplied from eight heats of 1015 steel reported to have the analysis shown in the following tabulation: Chemical Composition of 1015 Steel Heats Code Heat No. No. C Mn P S Si Cr Ni Mo 1 40915.12.44.010.024.15.18.11.04 2 41038.16.41.009.015.17.20,06.02 3 41037.13.46.010.022.16.20 06.02 4 40960.13.45.016.026.15.17.08.03 5 50682.14.50.009.023.21.09.09.04 6 50748.13.41.011.022.17.21.10.04 7 41095.15.45.012.030.30.08,09.02 8 11626.19.45.008.030.11.02.04(a).02 (a) + Cu. The prior history (melting practice and condition of heat treatment) was not reported.

3 RESULTS AND DISCUSSION Short-time tensile data were obtained for 1600~, 17000, 1800~, 1900~, and 20000F. The tensile tests, particularly at 17000F and higher, were run at a free head speed of 0. 2 inches per minute in order to decrease the amount of oxidation at these high temperatures and to more nearly equal the condition of strain that the material would probably undergo during fabrication processes. The tensile test data are tabulated in Table I. The variations in elongation, reduction of area, and tensile strength with temperature are shown in Figures 1, 2, and 3, respectively. Figures 1 and 2 show remarkable differences in ductility of the various heats in that they fall into either a high or low ductility group. The lower ductility heats had slightly higher tensile strengths. The variation in tensile strength between heats at any temperature was nowhere near as pronounced as were the variations in elongation or reduction of area. The cause of the differences in tensile data between heats is not apparent from the reported chemical compositions. A. possible explanation might be that there was a distinct difference in melting or deoxidation practice. Another possibility would be the presence of some contaminating element not normally analyzed. Inasmuch as the tests were carried out in the austenite region, it seems doubtful that prior processing could have been responsible.

TABLE I Short Time Tensile Tests: 1015 + Cr Steels Code Heat Tensile Strength Elongation Reduction of Area No, No. (psi) (%o in 2 in.) (%) 1600~F 1 40915 (a) 9,300 78.0 94.5 1 40915 9,850 71.0 73.0 2 41038 (a) 8,830 22.5 21.5 2 41038 9 700 24.0 23.5 3 41037 (a) 8,880 22.0 19.0 3 41037 8,800 21.5 21.5 4 40960 (a) 9,475 83.0 82.0 4 40960 10,450 82.0 86.0 5 50682 (a) 9,100 18.5 14.5 5 50682 9,700 16.5 16.5 6 50748 (a) 9,325 83,5 80.5 6 50748 9,550 78.5 90.0 7 41095 10, 125 20.5 18.5 8 11626 7,870 71.5 97. 5 1700~F 1 40915 7,725 73.0 97.0 1 40915 6,970 81.0 96.5 2 41038 7 825 20.0 17.5 3 41037 7,675 20.0 18.0 3 41037 8,075 21.5 21 5 5 50682 8,070 13.5 15.5 5 50682 7,750 15.0 14.5 6 50748 7,770 78.0 91.5 6 50748 7,700 77.0 94.5 7 41095 8, 150 17.5 16.5 8 11625 5,840 79.5 85.0 1800~F 1 40915 6,050 70. 0 98.5 3 41037 6,500 25.0 21.0 5 50682 6,350 13.0 13.0 6 50748 6,300 72.0 88.0 7 41095 6,650 15.0 15.5 8 11626 4,920 75.5 99.5

TABLE I, Continued Code Heat Tensile Strength Elongation Reduction of Area No. No. (psi) (% in 2 in.) (%) 1900~F 1 40915 4,900 68.5 97.5 3 41037 5,600 29.5 34.0 5 50682 5,780 17.0 17.5 6 50748 5,050 69.5 99.0 7 41095 5,720 19.5 20.5 8 11626 4,200 68.5 99.5 (b) 20000F 1 40915 3,880 77.0 99.5 (b) 3 41037 4,280 38.5 72.5 5 50682 4,540 30.0 41.0 6 50748 4,200 64.5 99.5 (b) 7 41095 4,875 30.0 37.0 8 11626 3,610 75.5 99.5 (b) (a) These tensile tests were run at a free head speed of 0. 1 inches per minute. All others were run at 0. 2 inches per minute. (b) Necked to a point.

NOTE: For Figures 1, 2, and 3 consult file copy.