Engineering Materials Assignment 2 Explain the graph below 80 Percent clongation 20 40 6 Brinell hardness, HB 30K) 20K) 100 Tensile strength, ksi 20 40 89 80 OL 0 0 10 20 Tensile strength 500 400 300 Hardness 200 Elongation 100 30 Percent cold work 40 Tensile strength, MPa M. Strocchia 1300 Senrictureal Austenite hardening temperature 1200 10% denite 1100 1000 Engineering Materials Assignment 2 Explain direct hardening carbon steels using the graph: Why do you heat to the austenite temperature range? Temperature, C IGOO 1500 700 Why do you need 100 Hardening temperature Heating to hardening temperature sufficient carbon content? Why do you rapid quench? Pearlite Structure is an annealed 1060 (0.6 C) steel at room temperature FCC Percent ca Rapid quench BCT (body-centered tetragonal) Structure after quenching Hours marcasite Determination of hardening temperature for a 0.6% carbon steel Engineering Materials :Assignment 2 Explain the following chart: Pure iron (0.5 ppm C, annealed) Iron +0.2%C (1020 steel, annealed) Iron + 0.2%C +cold work (1020 steel, cold rolled) Iron +0.8%C (1080 steel, annealed) Iron +0.8%0 (1080 steel, quench hardened to 50 HRC) 100 1000 10.000 MPa 50 100 500 1000 Yield strength (ksi) M. Strocchia Assignment 2 Explain the effect of tempering on the properties of a quench- hardened carbon steel (1040-1060) Ductility (% clongation) Tensile strength Tempering temperature Tempering temperature Hardness un Tempering temperature Tempering temperature Explain the following grapth Tensile strength (MPa) 400 600 800 1000 1200 600 60 500 400 Tensile strength Ductility 300 Recovery Recrystallization Grain growth Cold-worked and recovered grains Grain size (mm) 0.040 0.030 0.020 C.010 100 200 New grains 400 300 Annealing temperature (PC) 500 600 700 50 40 30 20 Ductility (%EL)