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Determination of Hydrogen Solubility in Fe–Mn–C Melts
Author(s) -
Lob Alexander,
Senk Dieter,
Hallstedt Bengt
Publication year - 2011
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.201000262
Subject(s) - solubility , hydrogen , materials science , hydrogen embrittlement , calphad , embrittlement , manganese , extrapolation , quenching (fluorescence) , thermodynamics , analytical chemistry (journal) , metallurgy , phase diagram , phase (matter) , chemistry , corrosion , mathematical analysis , physics , mathematics , organic chemistry , chromatography , quantum mechanics , fluorescence
Abstract High manganese steels are supposed to be sensitive to hydrogen embrittlement. This can be explained by increased hydrogen solubility in comparison to unalloyed steels. To minimise hydrogen pick up during melting operations, it is necessary to know accurately the hydrogen solubility as function of hydrogen partial pressure, temperature and Mn content. In this work in situ measurements of hydrogen content at 12, 18 and 23 wt.% Mn (and 0.6 wt.% C) using the Hydris® system are compared to pin‐tube measurements. Below about 7 ppm [H] both methods gave the same results and above 7 ppm [H] the in situ measurement showed slightly higher hydrogen contents because some hydrogen is lost during quenching with the pin‐tube method. The measured solubilities were compared with thermodynamic calculations. Using dilute solution theory with data developed for alloyed Fe‐based melts with up to 10 wt.% Mn gives reasonable results except that the hydrogen solubility is slighltly underestimated for the presently investigated Mn contents. This could be compensated by using an interaction parameter of e H Mn = –0.004 instead of e H Mn = –0.0012. A Calphad type extrapolation from the binary Fe–H, Mn–H and Fe–Mn systems gave results very close to the experimental ones. This work is a contribution from the collaborative research centre SFB 761 “Steel – ab initio ”.