High temperature Inconel vessel design
High temperature Inconel vessel design
(OP)
1. I want to calculate the external pressure that can be applied to an Inconel 600(UNS No. N06600) pipe (3" NB, 40 sch/ 10 sch) at 1000C. The data in ASME code for Factor A and Factor B is given upto 1200F i.e. 650C. How do I compute this value at 1000C.
2. The yield strength and the ultimate tensile strength values for this material are given in ASME Section II, Sub part D only upto 900F. How do I extrapolate these values to 1000C i.e. 1832F?
Thanks in advance.
2. The yield strength and the ultimate tensile strength values for this material are given in ASME Section II, Sub part D only upto 900F. How do I extrapolate these values to 1000C i.e. 1832F?
Thanks in advance.





RE: High temperature Inconel vessel design
If you need to determine actual ultimate tensile and yield strength values for this material beyond code recommended ranges, I would recommend you find a tech sheet on this material from Special Metals. They typically publish elevated temperature mechanical properties.
RE: High temperature Inconel vessel design
But read the rules carefully, to see if you can use this formula at tempreatures above 650C. The reason is that the material shifts form, and becomes very ductile at these temperatures.
RE: High temperature Inconel vessel design
Regarding the basic allowable stress, at the temperature you are considering, creep properties will probably govern the allowable stress, so the tensile strength and yield strength probably will not factor into determining an allowable stress.
If this is B&PV Code, a Code Case would be required to do this. If it is B31.3 Piping Code, you have certain responsibilities outlined in the Code with respect to determining material suitability and the allowable stress per the Code stress criteria.
In short, you need some high temperature expertise to try to do this.
RE: High temperature Inconel vessel design
RE: High temperature Inconel vessel design
Actually, the Inconel 601 would be a better selection for pipe material terms of creep rate or creep deformation. At 1800 deg F, the stress to produce a creep rate of 0.001%/hr is slightly over 1 Ksi versus 0.8 Ksi for Inconel 690. The Inconel 690 was designed to provide improved corrosion resistance at elevated temperature.
If you review the elongation properties for this material, the elongation increases to almost 100% above 1300 deg F. What this means is that you will probably need to significantly increase the wall thickness of the pipe to compensate for the increase in elongation above 1300 deg F, and to keep the stress value well below 1,000 psi to assure a creep deformation rate of 0.001%/hr, and to avoid rupture under 10,000 hrs.
What is your application that would require the use of ASME B&PV code or ANSI Piping codes? If you are simply using the code or piping standards as a guideline for design, and are under no obligation from a Jurisdictional or Regulatory requirement, you have several different approaches to calculate allowable stress. I will caution you that this is not simple task, and should be performed by an organization that has expertise in elevated temperature stress analysis.
RE: High temperature Inconel vessel design
N2 is a bad actor and well as several of the Alkaline Earth metal compounds. Trace amounts of Boron compounds do a number on the metal.
RE: High temperature Inconel vessel design