Investigation of part of the quaternary system Fe-Cr-Ni-Mn

Summary

• 1. By means of microscopic analysis, hardness and electrical resistance, an investigation was made of a triangular section of the tetrahedron of the quaternary system Fe-Cr-Ni-Mn. The section of the quaternary system chosen for investigation had as its base a section of the ternary system Fe -Cr -Ni parallel to the Fe -Cr side at a constant nickel content of 10% and a variation in chromium content from 0 to 100% and in manganese content from 0 to 100%.

• 2. In the iron corner of the section, the boundaries of the phase regions α,α + γ, γ, and σ were established and also a series of intermediate regions and a phase diagram of the alloys was constructed.

• 3. The dependence of the changes in hardness and electrical resistance on the composition and phase structure of the quaternary alloys was established. Alloys were found with a high ohmic resistance, corresponding in composition to 49.7% Mn, 38% Cr, 5% Ni and the rest Fe. The specific electrical resistance of this alloy was 1.31 Ω /mm².

• 4. A total of 15 different phase regions were found in the studied part of the quaternary system Fe -Cr -Ni -Mn. In the phase diagram of the studied section of the quaternary system, a considerable region was occupied by quaternary austenite (γ) solid solutions with manganese, which are of practical interest as a basis for a search for new chromium-nickel-manganese steels of the austenite class.