- Q1 Austenitized 40 Mm Diameter 5140 Alloy Steel Bar Is Quenched In Agitated Oil Predict What Is The Rockwell Hardness 1 (60.89 KiB) Viewed 36 times
Q1: Austenitized 40 mm diameter 5140 alloy steel bar is quenched in agitated oil. Predict what is the Rockwell hardness of this bar will be at (a) its surface and (b) its center (c) What do you think about the difference in hardness number between the center and surface (d) Differentiate between hardness and hardenability (e) Rank the steels in the figure below from lowest to highest hardenability and explain why. 600- Bar diameter (mm) 300 -150 0755 100 80 60 40 20 0 0 Cooling rate at 700°C (°C/sec). 0 5 25 S 10 12.5 8 5.5 4 M-R 3/4-R Agitated oil للا humo 15 20 3 ½/2 Distance from quenched end. De (Jominy distance) Bar diameter (in.) 25 mm 1 in. Where (C = center, S = surface, M-R = mid-radius) Hardness (Rockwell C) 28849323959 65 60- 55- 50 45- 40- 30 25 20- 15- 10 0 1 24 6 8 10 12 14 16 18 20 22 24 26 28 30 Distance from quenched end (sixteenths of an inch) 10 5140 20 30 Distance from quenched end (mm) 40 4340 9840 4140 8640 L 32 50