ASME SA335 P22 boiler pipe should have high creep strength and rupture strength, good thermal and mechanical fatigue resistance, good oxidation resistance and gas corrosion resistance, and good microstructure stability. Among them, creep strength and rupture strength are the most important in ASME SA335 P22 boiler pipe.
The ways to improve the strength of ASME SA335 P22 boiler pipe are:
Solid solution strengthening: adding elements different from the base metal atom size (chromium, tungsten, molybdenum, etc.) causes distortion of the matrix metal lattice, adding elements (such as cobalt) that can reduce the stacking fault energy of the ASME SA335 P22 boiler pipe matrix and adding can slow down the matrix Elemental diffusion rate elements (tungsten, molybdenum, etc.) to strengthen the matrix.
Precipitation strengthening: The second phase (γ┡, γ", carbide, etc.) is precipitated from the supersaturated solid solution by aging treatment to strengthen the ASME SA335 P22 boiler pipe. The γ┡ phase is the same as the matrix, and is a face-centered cubic structure. The lattice constant is similar to the matrix and coherent with the crystal. Therefore, the γ ┡ phase can be uniformly precipitated in the form of fine particles in the matrix, hindering the movement of dislocations, and producing a significant strengthening effect.
Grain boundary strengthening: At high temperatures, the grain boundary of ASME SA335 P22 boiler pipe is a weak link (see interface), and the addition of trace amounts of boron, zirconium and rare earth elements can improve the grain boundary strength. This is because rare earth elements can purify grain boundaries, boron and zirconium atoms can fill grain boundary vacancies, reduce the grain boundary diffusion rate during creep, inhibit the aggregation of grain boundary carbides and promote the spheroidization of grain boundary second phase.
We can supply the ASME SA335 P22 boiler pipe with high quality and best service for customers. If you have any need in ASME SA335 P22 boiler pipe, please contact us freely. We will solve your any questions about ASME SA335 P22 boiler pipe. Welcome to contact us!
