SA213 T91 high-pressure seamless steel pipe is a material between 12CrlMoV and stainless steel. Its preparation is an improved 9Cr-1Mo high degree martensite heat resistant steel, which has high fracture strength and hot corrosion resistance.
SA213 T91 high-pressure seamless steel pipe is an ideal pipe for boiler heating surface tube banks in the temperature range of 600~650 ℃. It has good soothing reaction performance, higher thermal conductivity than austenitic steel, similar linear expansion coefficient to pearlite steel, and lower price than austenitic steel.
When the operating temperature is below 620 ℃, the allowable stress of this steel is higher than that of austenitic stainless steel, especially for dissimilar steel welded joints made with austenitic stainless steel. Its thermal strength performance can reach the performance level of the same type of steel pipe welded joint. Compared with SA-213TP304H, the thermal fatigue resistance of welded joints is very good.
Practice has shown that SA-213T91 can partially replace SA-213TP304H in the manufacturing of serpentine tube banks on the heating surfaces of boiler superheaters/reheaters, and has significant economic benefits.