By thermal and microscopic analyses 110 Fe-Fe₃C-FeS-Mn alloys containing about 0.45%, 0.88% and 1.9% Mn have been studied. As to these three series of alloys, isothermal, projectional and structural diagrams have been constructed. As the manganese content increased, the range in which two liquid phases coexis'ed widened in the direction of the low carbon and low sulphur composition side. The critical point of the monotectic reaction surface in alloy series containing about 1.9% Mn was about 1355°C, 7.2% S and 0.53% C, while that in those containing no manganese was 1, 300°C, 8% S and 1.07% C. The experimental result has made clear the mechanism of desulphurization and the decrease of the red shortness in steel due to addition of manganese. As the manganese content increased, the monotectic temperature rose at which the sulphide-rich-melt was separated from a homogeneous melt and came up to the surface forming slag. It is a well-known fact that in steels containing some amount of manganese the manganese-rich sulphide globules exist in the austenite grains, and the red shortness is little. Moreover, as the manganese content in creased, the binary sulphide eutectic temperature rose, at which the sulphides were separated on grain boundaries of austenite. Therefore the melting of the boundaries takes place at higher temperature and the red shortness is decreased

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The 18/8 series of stainless steels which are receiving the attention of both the engineering world and the general public because of their excellent qualities have certain properties which at times interfere with their fullest application. These properties include: excessive hardening on cold working, poor fabricability, loss of ductility at both low and moderate high temperatures, loss of corrosion resistance and intercrystalline corrosion.
This paper shows that much of this is due to a physical instability characteristic of certain austenitic alloys. The range of composition subject to this trouble has been mapped out. This paper is purposely limited to a description of steel containing about 18 per cent. of chromium and 8 per cent. of nickel.
When this class of steel is heated in the range of 500°to 900°C and then cooled, the material is attacked by most corrosive media in an intercrystalline manner. The cause and prevention of this defect has been fully discussed in this paper and the following conclusion has been drawn: Pretreatment materially influences the corrosion resistance of the alloys and the addition of certain chemical elements renders the alloys considerably resistant to corrosion.

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