R Subbarayalu
Mechanical
Dear Sir/Madam,
We are making P91 material piping for high pressure & temperature steam applications in super critical boilers.
For this, we take induction pipe bending process and then do Normalizing & Tempering heat treatment operations.
Our question is, whether it is allowed to use GREASE for measuring the pipe wall thickness using the D meter, on the hot bent P91 Pipe before the Normalizing & Tempering heat treatment operations.
It seems that no hydro-carbon based materials should not have contact with the P91 Pipe surface (after the induction bending operation) but before the N & T.. due to the metallurgical reasons .
Please clarify with technical literature support.
R Subbarayalu
We are making P91 material piping for high pressure & temperature steam applications in super critical boilers.
For this, we take induction pipe bending process and then do Normalizing & Tempering heat treatment operations.
Our question is, whether it is allowed to use GREASE for measuring the pipe wall thickness using the D meter, on the hot bent P91 Pipe before the Normalizing & Tempering heat treatment operations.
It seems that no hydro-carbon based materials should not have contact with the P91 Pipe surface (after the induction bending operation) but before the N & T.. due to the metallurgical reasons .
Please clarify with technical literature support.
R Subbarayalu
