GH99 is a Ni-Cr based precipitation hardening deformation high temperature alloy, which can be used for a long time below 900°C, and the short time maximum temperature can reach 1000°C. GH99 alloy is strengthened by adding chromium, cobalt, tungsten and molybdenum for solid solution strengthening, aluminium and titanium to form aging-strengthened phases, and boron, cerium and magnesium to purify and strengthen the grain boundaries.GH99 alloy has a higher thermal strength, stable organisation and satisfactory cold and hot machining, forming and welding properties. GH99 alloy has high thermal strength, organisational stability, and has satisfactory hot and cold processing forming and welding process performance.GH99 is suitable for the manufacture of aero-engine combustion chambers and fuel combustion chambers and other high-temperature welded structural parts.The main products of GH99 are hot-rolled bars, plates, wires and forgings. With the alloy manufactured by the large plate structure, can be used directly after solid solution Treatment without aging Treatment. The alloy has not been found to have any harmful phases after long-term aging at 700℃~950℃.