Machine Elements in Mechanical Design Essay Example for Free

Machine Elements in Mechanical Design Essay Answers to Selectecj Problems Given here are the answers to problems for which there are unique solutions. Many of the problems for solution in this book are true design problems, and individual design decisions are required to arrive at the solutions. Others are ofthe review question form tor which the answers arc in the text ofthe associated chapter It should also be noted that some ofthe problems require the selection ot design factors and the use of data from charts and graphs. Because of the judgment and interpolation required, some ofthe answers may be slightly different from your solutions. AISI 1080. 28. AISI 5160 OQT 1000 is a chromium steel, having nominally 0. 80 percent chromium and 0. 60 percent carbon, a high carbon alloy steel. It has fairly high strength and good ductility. It was through-hardened, quenched in oil, and tempered at 1000Â °F. 29. Yes. with careful specitlcadon ofthe quenching medium. A hardness of HRC 40 is equivalent to HB 375. Appendix 3 indicates that oil quenching would not produce an adequate hardness. However, Appendix 4-1 shows that a hardness of HB 400 could be obtained by quenching in water and tempering in 700Â °F while still having 207f elongation for gciod ductility. 3. AISI 200 and 300 series 34. A hardness of 750 HB is extremely hard and characteristic of as-quenched high alloy steels, 15. The HRB scale is normally limited to HRB 100. 16. The HRC hardness is normally no lower than HRC 20. 17. The given relationship between hardness and tensile strength is only valid for steels. 18. Charpy and Izod 19. Iron and carbon. Manganese and other elements are often present. 20. Iron, carbon, manganese, nickel, chromium, molybdenum. 21. Approximately 0. 40 percent. 22. Low carbon: Less than 0. 30 percent