athomas236
Mechanical
Based on a paper presented at the 2004 ASME P&PV Conference, I understand that any material supplier that wants a new material included in the Code has to provide details of the mechanical properties from three heats and make recommendations regarding the specified compositional ranges of the major alloying elements.
For creep enhanced materials like P91, the creep strength properties are dependent on achieving a specific microstructure which is sensitive to changes in composition. As a result a material may have a composition that falls within the Code specified ranges but not the mechanical properties upon which the Code allowable stresses are based.
To address this ASME will, I understand, make the allowable compositional ranges more closely reflect those of the three heats upon which the Code allowable stresses are based.
This is good for future approvals of new materials but the question in my mind is "what about materials like P91 that have already been approved".
Is it possible to obtain the data upon which P91 was originally approved.
For creep enhanced materials like P91, the creep strength properties are dependent on achieving a specific microstructure which is sensitive to changes in composition. As a result a material may have a composition that falls within the Code specified ranges but not the mechanical properties upon which the Code allowable stresses are based.
To address this ASME will, I understand, make the allowable compositional ranges more closely reflect those of the three heats upon which the Code allowable stresses are based.
This is good for future approvals of new materials but the question in my mind is "what about materials like P91 that have already been approved".
Is it possible to obtain the data upon which P91 was originally approved.
