(i) A material made of steel has a tensile strength of 120,000 psi. Give a reasonable estimate of its fatigue strength. (ii) State when you would use the creep strength of a material as a basis for...

(i) A material made of steel has a tensile strength of 120,000 psi. Give a reasonable estimate of its fatigue strength. (ii) State when you would use the creep strength of a material as a basis for structural design. (iii) Explain in detail what you understand by elastic and plastic deformations in (a) steel and (b) copper alloy (yellow brass). Q105; Determine the materials for the following use: (i) steel for application in the Arctic region, needing a Charpy V-notch impact energy higher than 80 lb. ft., at a temperature of –18°C; (ii) steel for use in a liquefied natural gas (LNG) tanker that is in contact with LNG (at a temperature of –150°C); and (iii) steel for use in the equatorial belt, where temperatures can rise to a maximum of +50°C.