Four heat treatment schedules were applied to 14.6 wt pct Cr-2.2 wt pct Mn-1 wt pct Ni cast iron to improve its machinability: (a) one-step continuous annealing [holding at 1123 K (950 °C), 2 hours, cooling at 20 to 150 K/h], (b) three-step isothermal annealing [1123 K (950 °C), 2 hours + 923 K (650 °C), 6 hours + 998 K (725 °C), 15 hours], (c) two-step isothermal annealing [923 K (650 °C), 6 hours + 998 K (725 °C), up to 25 hours], (d) quenching [1123 K (950 °C), 2 hours] and tempering [998 K (725 °C), up to 15 hours]. Heat treatments (a) and (b), which include high-temperature holding at 1123 K (950 °C), result in secondary carbide precipitation, and lead to a “martensite/austenite” or “martensite/austenite/pearlite” matrix and a bulk hardness of 56 to 62 HRC with poor machinability. Heat treatments (c) and (d) provide a matrix of “ferrite + granular carbides” with a bulk hardness lower than 40 HRC. Quenching and tempering result in the elimination of retained austenite to 11.6 vol pct. The kinetics of spheroidization and coagulation of eutectoid carbides and carbides as precipitated from martensite are presented and discussed. Drill testing showed that after quenching and tempering, cast iron has a superior machinability compared with other heat treatments.
Metallurgical and Materials Transactions A – Springer Journals
Published: Jun 5, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera