17-7PH precipitation hardening stainless steel consumable electrode is prepared by 35 t electric arc furnace- AOD decarbonization- LF refining- ingot casting process

and 2 t electroslag ingot is obtained by gas shielded electroslag furnace. The change law of inclusion number

size and composition in 17-7PH steel before and after electroslag remelting are analyzed by ASPEX scanning electron microscope

and the morphology and type of inclusions in steel is further observed by SEM-EDS. The experimental results show that

after electroslag remelting

the oxygen content decreases from 6.6 x 10

-6

to 5.7 x 10

-6

and the nitrogen content decreases from 200 x 10

-6

to 180 x 10

-6

. The types of inclusions don't change before and after remelting

but

the total number of inclusions decreases significantly

especially the number and size of large particle inclusions decrease significantly. The total inclusions in electroslag ingot are mainly AIN inclusions

which are large in size and most in quantity. In order to improve the cleanliness of 17-7PH steel electroslag ingot

it is necessary to reduce the nitrogen content of consumable electrode as much as possible

so as to reduce the formation of AIN inclusions formed during electroslag remelting.