Jominy Test – Assignment Example

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The table 1.0 above shows the results from the experiment where three samples were tested at different temperature and the HRC were recorded at the same distance. Sample 817 shows higher HRC at zero distance followed by sample 377 and sample 844 having the lowest HRC. With increase in distance, sample 377 shows increase in HRC but sample 817 shows declining trend. This behavior of different samples is shown in the above table. 3.0Jominy CurveAfter the experiment were done and results were recorded in table 1.0 above Jominy curve was drawn for each sample tested.

This can be presented in the figures below; Figure 1: Sample 817Figure 2: Sample 844Figure 3: Sample 377The three samples, which is sample 817, 844 and 377 were done and the above three figures were recorded. This was done at different distance and the change at different samples were recorded. The Jominy curves shown above gives the three different shapes after the graph were drawn. A sample graph of hardenability for three different steels. The graph plots the hardness measurements as a function of distance from the quenched end as obtained from the Jominy test.

From the test, we can establish which type of steel or materials were used in the sample taking in consideration the distance of the bent in each and every sample in the graph above. From the three figures, sample 844 in figure 2 above shows high level of hardenability compared with the remaining sample 377 and sample 817. Sample 817 shows decline in hardenability with increase in distance while sample 377 shows increase in hardenability with increase in distance. This help use to identify the type of the materials or alloys of steel used.

They include: Sample 377 is 4340 steelSample 817 is 1040 steel andSample 844 is 844 steel 4.0Microstructures to the rate of coolingThe three specimens utilized as a part of the trial indicates divergence in hardenability conduct and these must be clarified by the nearness of different components like chromium and molybdenum in the steel permit. Typically the amalgam components exhibit in the steel defer the austenite to pearlite bainite response. These permits more martensite to frame for a specific cooling rate yielding and more prominent hardness. The conduct of the three permits are appeared in the above chart in figures.

From the figures, it can be seen that the extinguished end is cools quickly and regularly displays the greatest hardness. It ought to be seen from the assumption that 100% martensite is the item at this position for generally steels. Cooling rate regularly diminishes with the separation from the extinguished end and the hardness of the material decreases as appeared in the figures above. With decreasing in cooling rate there is additional time permitted from carbon dissemination and the arrangement of a more noteworthy extent of the milder pearlite that might be blended with the martensite and bainite.

This is sufficient confirmation that the steel which is exceptionally hardenable will retail expansive hardness values for moderately more separation than the rest while at a steel with low hardenability will go for shorter separation that it is less demanding and easy to relate hardness to cooling than to remove from the extinguished end of a standard Jominy example.

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