Question

For tensile testing, six 1018 steel tensile bars were homogenized at 950°C and then each was subjected to one of the following heat treatments:

• water quenching (WQ)
• water quenching followed by a 1 hour anneal at 300°C (WQ + 300)
• water quenching followed by a 1 hour anneal at 500°C (WQ + 500)
• Oil quenching (OQ)
• Air cooling (AC)
• Furnace cooling (FC)

Carbon Steels: 1019 °C A 800 A A+F 700 6001 A+F+P F+P 500 -Ms TEMPERATURE 400E Mgo M90 300 200 100 I MIN THOUR I DAY 1 WEEK 0 0.5 2 5 10 105 106 102 103 104 TIME - SECONDS 3. What phases are expected in the WQ specimens annealed at 300 and 500°C?-

Answer 1

ليمي from the given TTT diagram we can say that Due to the water quenching (wo) Austenite phase of 1018 Steel is converted in to Martensite [Mgo = 90% of total phase is Martensite 1 on Now further heating of sample at 500c for 1 hr (3600 sec), Martensite is converted Ferritet Pearlite. In to While on heating at 30oc for Ihr (3600 xed Mortensite is semain Mortensite (more Stable and uniform) so wat anneal @ 300c wat anneal @ sooc Martensite Ferrite & Pearlite CS Scanned with CamScanner