Product features

The 690 alloy has excellent capabilities of anti-intergranular corrosion and anti-intergranular stress corrosion cracking, and is mainly used the material of the heat transfer tube in the pressurized water reactor nuclear power plant steam generator. The material for the heat transfer tube in the pressurized water reactor nuclear power steam generator has undergone a development process, including 304 austenitic stainless steel, 600 alloy, 800 alloy, and 69 alloy. The research on the corrosion failure of 600 alloy in service shows that intergranular corrosion and intergranular stress corrosion cracking are the main problems. There has no report of damage of the 690 alloy as the material of the heat transfer tube in the pressurized water reactor nuclear power plant steam generator since it was put into in the 1990s. 

Application scope domain

690 alloy is mainly used for the heat transfer tubes of the steam generator in pressurized water reactor nuclear power plants, which is the core technology the steam generator. At present, among the pressurized water reactor nuclear power plant units already in operation in China, only Qinshan Phase I uses 800 alloy while Qinshan Phase II, Daya Bay and Lingao nuclear power plants all use 690 alloy as the material for the heat transfer tubes of the steam generator Most of the pressurized water nuclear power plants under construction and planned also adopt 690 alloy as the material for the heat transfer tubes of the steam generator.