Abstract:It has been proved that HR3C steel has good high temperature performance, corrosion resistance and welding performance, and it can be used for ultrasupercritical power plant boiler superheater and reheater tubes. It was found that there is no more difference between run pipe intensity and spare pipe intensity of HR3C, but the brittleness increases obviously，the break elongation and impact toughness significantly reduced of run pipe. A large number of grain boundary carbides in flaky distribution, which reducing the grain boundary strength and making the material easy to brittle fracture along grain boundaries.

Keywords:HR3C, austenite, heat resistant steel, ultra supercritical