tprimaterial
Materials
- Aug 2, 2005
- 9
Dear members,
delta-ferrite is deleterious to the creep properties and toughness of Martensite steels ,such as P91 and P92. delta-ferrite is often observed in weld metal and at fusion line. If the PWHT temerature exceed the transformation temperature and with normal cooling rate (such as 80-150 centidgree per hour), will delta ferrite form?
and to what level of the ferrite content, it will be unaceptable to use the material? 1%, 3% or 5% and so on, it has no exact advice about this in ASME A 335.
thanks!
delta-ferrite is deleterious to the creep properties and toughness of Martensite steels ,such as P91 and P92. delta-ferrite is often observed in weld metal and at fusion line. If the PWHT temerature exceed the transformation temperature and with normal cooling rate (such as 80-150 centidgree per hour), will delta ferrite form?
and to what level of the ferrite content, it will be unaceptable to use the material? 1%, 3% or 5% and so on, it has no exact advice about this in ASME A 335.
thanks!