Zr-4 Alloys

Application of Zr-4 alloys

Zr-4 alloys are used as structural materials in pressurized water reactors for nuclear power plants.

Chemical composition ranges of Zr-4 alloys
Grade	ω/%
Grade	Sn	Nb	Fe	Cr	O
Zr-4	1.20-1.70		0.18-0.24	0.07-0.13	0.08-0.16

Comparison of corrosion weight gain between conventional Zr-4 and improved Zr-4 at 500 ℃ and 10.3MPa
Grade	Status	400℃, 3days, Δm/mg·dm^-2	400℃, 3days+500℃, Δm/mg·dm^-2
Grade	Status	400℃, 3days, Δm/mg·dm^-2	4h	8h	16h	Surface condition
conventional Zr-4	R	12.98	54.05	530.59	-	4h blister,8h cover completely and drop powder
improved Zr-4	R	15.16	17.00	24.06	29.97	not blister
improved Zr-4	SR	20.47	24.87	31.52	37.39	blister at the top corner

The relationship between corrosion weight gain and time of Zr-4 alloys coated tube samples processed by different processes