ENTC 207 2nd Exam question well answered 2023

ENTC 207 2nd Exam As ____ increases, tensile strength goes down - correct answer temperature ____ is most popular/common method of heat treating - correct answer Stress Relieving Little circular pieces are called what? - correct answer Ferrite ____ looks like a very tempered martensite - correct answer Bainite This method of heat treating is used for specialized, thin pieces that would normally be bent or distorted if heat treated like normal - correct answer Austempering Another heat treating method used for thin pieces that need to be hardened without bending or distorting. (Blades of knives) - correct answer Martempering _____ is the ability to form martensite - correct answer Hardenability ____ is where only a certain part of material is heated - correct answer Localized Hardening What is 1 method of achieving localized hardening? - correct answer Flame Hardening Above ____ temp. forms martensite - correct answer AC_3 ____ is used to change mechanical properties of entire material - correct answer Heat Treated What does BCT stand for and what is it doing? - correct answer Body Centered Tetragonal. It is elongated, trying to sequence back to its normal shape, but carbon is in the way ____ is very hard, high strength, and no grain boundaries - correct answer Martensite Martensite is composed of this "needle-like" material - correct answer acicular When hardening a steel, you have 2 options to form a certain type of element. (%) What are they? - correct answer 1. Under .8%, then only martensite will form 2. Over .8% will form Martensite AND Cementite What is quenching? - correct answer Cooling metal down after comes out of surface List the cooling methods from slowest to fastest: Oil Quench Air Quench Water Quench Forced Air Quench Brine Quench Furnace Cooling - correct answer 1. Furnace Cooling 2. Air Quench 3. Forced Air Quench 4. Oil Quench 5. Water Quench 6. Brine Quench _____ & _____ determines how fast object cools - correct answer Carbon Content & Alloy Content How fast do we want the material to cool? - correct answer Slowest-fast cool method, because if it cools too fast it will crack the metal What is through hardening? - correct answer Martensite is formed throughout all of material when cooled