Jerrod Miller 600 Posted April 17, 2019 Share Posted April 17, 2019 Ran across this interesting table and graph, thought I would share. The source cited (4) is Siebert, Doane & Breen, The Hardenability of Steels, ASM, 1977. Moral to the story: Not only does an increase in carbon increase the ability of martensite to form, but it also corresponds to an increase in hardness for the martensite as well. I don't have the source material at hand, but I think it is safe to assume that "excessive" alloying elements besides Fe and C will also change the overall hardness. The paper I was reading that this chart appeared in did not go into any specifics in this case either. 2 Link to post Share on other sites
Joël Mercier 716 Posted April 17, 2019 Share Posted April 17, 2019 I did also read that the maximum amount of carbon that will increase hardness in simple carbon steel is around 0.9%. Is that right? This would explain why Aldo chose to use 0.91%C in his W2. Link to post Share on other sites
Gary Mulkey 1,445 Posted April 17, 2019 Share Posted April 17, 2019 Interesting. It appears that 99.9% martensite can be achieved with .5%C. I was under the impression that it would take .7%. Gary ABS,CKCA,ABKA,KGA Link to post Share on other sites
Alex Middleton 831 Posted April 17, 2019 Share Posted April 17, 2019 (edited) Out of curiosity, what % of martensite can the average backyard smith expect to yield using simple steels and quenching at decalescense? Edited April 17, 2019 by Alex Middleton Link to post Share on other sites
Jeremy Blohm 575 Posted April 17, 2019 Share Posted April 17, 2019 Thank you Jerrod for sharing. Link to post Share on other sites
Jerrod Miller 600 Posted April 17, 2019 Author Share Posted April 17, 2019 2 hours ago, Gary Mulkey said: It appears that 99.9% martensite can be achieved with .5%C. I was under the impression that it would take .7%. I can't say for sure, but my understanding would be that they are doing a microscopic (likely Vicker's) hardness on a localized patch of martensite, avoiding the ferrite/pearlite around it. The sample as produced would not be 100% martensite. 1 Link to post Share on other sites
Jerrod Miller 600 Posted April 17, 2019 Author Share Posted April 17, 2019 28 minutes ago, Alex Middleton said: Out of curiosity, what % of martensite can the average backyard smith expect to yield using simple steels and quenching at decalescense? Assuming something like 1084, pretty much 100%. Link to post Share on other sites
Alex Middleton 831 Posted April 17, 2019 Share Posted April 17, 2019 Thanks Jerrod, that's good to know. Link to post Share on other sites
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