Heat treatment temperature and the choice of value for

It will be noted that each hydrogen removal curve consists of a band and that the lower the temperature the wider the band. This 

16 Schematic illustration of the use of hydrogen removal curves. At time txhr the percentage of original hydrogen remaining at the centre of the material will be between Hz, max and Hz min. 

Heat treatment temperature T, °C Material half-thickness. L,mm 

17 Variation of overall diffusivity coefficient, D, with temperature. 

The way in which the diffusivity coefficient varies with temperature is shown in Fig. 5.17. This figure can be used to select values of D for all future calculations. Table 5.3 lists approximate values of the overall diffusivity coefficient for a number of materials typical 

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