Abstract:The microstructure and tensile bond strength of NiCrSiB coating on GH907 alloy samples before and after heat treatment were analyzed and compared by optical microscope and tensile testing machine. The salt-coated hot corrosion, galvanic corrosion and salt fog corrosion of the coatings after heat treatment were analyzed and studied. The results show that the bonding form of NiCrSiB coating is changed from physical bonding of particle accumulation to metallurgical bonding after heat treatment, The microstructure characteristics such as holes in the coating were significantly improved. The tensile bond strength of the coating decreases with the increase of the thickness both before and after heat treatment, and the bond strength of the middle section of the coating thickness is relatively stable after heat treatment. The salt-coated hot corrosion of coating is proportional to the corrosion time. Galvanic corrosion shows that the potential of the coating is lower than that of the base material. The yellow flow marks produced by the saltfog corrosion test of the coating are mainly the accumulation products of FeCl3 and FeCl2 on the microporous structure of the coating surface, which are formed by the Cl^-1 ion in the salt spray and the active Fe element in the coating during the long-term contact.