| Description |
vii, 97 leaves : illustrations, photographs ; 29 cm |
| Summary |
"An experimental investigation was conducted in order to study the relationship between temperature, time and the decomposition of austenite in Tungsten steel of a given composition - and to plot the T-T-T Diagram for this steel. The steel was prepared, homogenized and cut into identical specimens for further heat treatment and metallographic inspection. Precautions were taken to prevent these specimens from decarburizing during any heat treatment. This experimental work may be divided into three main parts I. Determination of the critical temperature range; i.e. the range of temperature Ae₁ and Ae₃ above which austenite is stable and below which it tends to transform to other products. Both the dilatometric and metallographic methods were used for this purpose and the results obtained were in close agreement with each other. II. Isothermal decomposition of austenite at constant subcritical temperatures - and the measurement of this transformation as a function of both temperature and time. (Using the Isothermal transformation metallographic technique developed at the U.S. Steel Research Laboratory). III. Determination of the martensite transformation range (i.e. M[sub s] & M[sub f]) - using the metallographic technique. Each part is discussed separately and at length since the technique used in each one of them is quite different from the two others. The T-T-T Diagram according to this investigation is a simple 0-type shape of curve - and by comparing this diagram with other diagrams for similar carbon steels, it is found that Tungsten is effective in moving the nose of the C-curve to the right but not as effective as other carbide forming elements such as Chromium. Tungsten is also found to be slightly effective in lowering the martensite formation range. The present investigation may be regarded as intended to plot and introduce a new T-T-T Diagram that has not yet been investigated"--Abstract, leaves i-ii. |
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