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Influence of the metalloids on the properties of cast iron
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CURRENT
TOPICS.
Influence of the Metalloids on the Properties of Cast Iron., H. I. COE. (J~otl nlzd Sreel Irzst., May, I913.)-American washed iron was melted under charcoal in a graphite crucible, and when melted suitable alloys of the metalloids were added to form a series of 54 alloys, containing carbon 3.0, silicon from 0.4 to 2.24, manganese from 0.14 to 2.22, sulphur 0.11 to 0.45, phosphorus 0.30 to 2.88 per cent. Transverse strength, deflection, tensile, and hardness tests were made and the results tabulated. The conclusions are: (I) Silicon decreases the strength and hardness of cast iron, owing to its effect in promoting the decomposition of iron carbide. (2) Manganese to the extent of 0.5 per cent. softens silicious gray irons, owing to its effect on the condition of the carbon; the strength is (3) The influence of increased by the addition of manganese. sulphur is largely determined by the silicon present. Carefully controlled, it should be of considerable value to the iron founder in (4j In the absence of mixing his iron for any particular purpose. manganese, and with about 2 per cent. silicon present, very strong gray irons may be obtained if the percentage of sulphur be judiciously raised. (5) Phosphorus, up to about I per cent., is useful. It confers fluidity, slightly increases the strength, and also slightly diminishes the hardness of the metal. A higher percentage gives a hard brittle material. The influence of the metalloids on the pearlite formation was also investigated, and the cooling curves of six phosphoric irons are given. The paper includes nine microphotographs. A New Use for Metallic Cobalt. ANON. (Byass Would, ix, 6, 217.)-From an article in the Iron~or~gcr it appears that cobalt may be largely used in steel manufacture. Steel experts in Sheffield are experimenting with a new grade of high-speed steel which contains a small proportion of cobalt in addition to tungsten, vanadium, and other usual ingredients. The effect of cobalt is to intensify the characteristic qualities of tungsten and vanadium and to impart to the tools increased speed and durability. Cobalt steel is already made in America and Germany, and some is offered in England at very high prices. The Sheffield steel makers will not offer this new steel to the engineering world till experiment has demonstrated beyond doubt its permanent commercial value, and the particular purA small quantity has been made in poses for which it is adapted. Sheffield, and some manufacturers have been asked to supply it. Cobalt is found in Ontario, and at present the supply is limited, but there is plenty of ore which could be mined if a regular demand Cobalt steel arose. The current price is $2500 to $30~10 per ton. will be more expensive than the best vanadium steels, and it is not thought in Sheffield that it will supersede the present high-speed steels to any considerable extent, although it will be advantageous for various purposes. Experiments as to the effect of cobalt on carbon steel mixtures are being made.
CURRENT
TOPICS.
Influence of the Metalloids on the Properties of Cast Iron., H. I. COE. (J~otl nlzd Sreel Irzst., May, I913.)-American washed iron was melted under charcoal in a graphite crucible, and when melted suitable alloys of the metalloids were added to form a series of 54 alloys, containing carbon 3.0, silicon from 0.4 to 2.24, manganese from 0.14 to 2.22, sulphur 0.11 to 0.45, phosphorus 0.30 to 2.88 per cent. Transverse strength, deflection, tensile, and hardness tests were made and the results tabulated. The conclusions are: (I) Silicon decreases the strength and hardness of cast iron, owing to its effect in promoting the decomposition of iron carbide. (2) Manganese to the extent of 0.5 per cent. softens silicious gray irons, owing to its effect on the condition of the carbon; the strength is (3) The influence of increased by the addition of manganese. sulphur is largely determined by the silicon present. Carefully controlled, it should be of considerable value to the iron founder in (4j In the absence of mixing his iron for any particular purpose. manganese, and with about 2 per cent. silicon present, very strong gray irons may be obtained if the percentage of sulphur be judiciously raised. (5) Phosphorus, up to about I per cent., is useful. It confers fluidity, slightly increases the strength, and also slightly diminishes the hardness of the metal. A higher percentage gives a hard brittle material. The influence of the metalloids on the pearlite formation was also investigated, and the cooling curves of six phosphoric irons are given. The paper includes nine microphotographs. A New Use for Metallic Cobalt. ANON. (Byass Would, ix, 6, 217.)-From an article in the Iron~or~gcr it appears that cobalt may be largely used in steel manufacture. Steel experts in Sheffield are experimenting with a new grade of high-speed steel which contains a small proportion of cobalt in addition to tungsten, vanadium, and other usual ingredients. The effect of cobalt is to intensify the characteristic qualities of tungsten and vanadium and to impart to the tools increased speed and durability. Cobalt steel is already made in America and Germany, and some is offered in England at very high prices. The Sheffield steel makers will not offer this new steel to the engineering world till experiment has demonstrated beyond doubt its permanent commercial value, and the particular purA small quantity has been made in poses for which it is adapted. Sheffield, and some manufacturers have been asked to supply it. Cobalt is found in Ontario, and at present the supply is limited, but there is plenty of ore which could be mined if a regular demand Cobalt steel arose. The current price is $2500 to $30~10 per ton. will be more expensive than the best vanadium steels, and it is not thought in Sheffield that it will supersede the present high-speed steels to any considerable extent, although it will be advantageous for various purposes. Experiments as to the effect of cobalt on carbon steel mixtures are being made.