Abstract:
Studies were
made on the mechanical properties obtained after aging at
540～600℃ for 0～5000h and 570℃ creep hardness of the
heat-resisting steels 20Crf1Mo1VTiB and 20Cr12MoWV(C422), which
had been oil-quenched from 1050℃, temperd at 700℃ for 4h. It was
established that the comprehensive mechanical properties and
high temperature stability of 20Cr1Mo1VTiB steel are superior
to those of C422 steel under the conditions of the present
research. As the L-M parameter P=T(20+lgt) increases, both
strength and hardness of the above steels decrease linearly
along a broken line with two different slopes. In the same way,
the creep hardness of the above steels decrease as the holding
time lgt(s) at 570℃ increases. Corresponding linear equations
were obtained, by making use of which it is possible to predict
long-time properties from short-time properties.
Key words:
Long-time aging L-M parameter Mechanical property Heat resisting steel
Manuscript received on January 3, 1990; revised manuscript
November 15, 1991
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