As the requirement for included element C

P

S and Si content in ultra-pure austenite steel 005Cr25Ni20 (% ：24 ~26Cr

19 〜22Ni) are very low i. e. (%) ：≤0. 010C

≤0. 010S

≤0. 010P and W≤0. 15 Si

the steel is smelted by 3 t vacuum induction furnace 4- vacuum consumption remelting furnace steelmaking process. With using quality pure iron (% ： 0. 009C

0. 035Si

0. 001 2S

0. 004 5P)

high pure chromium iron (%: 0. 010 - 0. 021C

0. 11 - 0. 13Si

0. 002 5 ~0. 005 OS

0. 001 5 ~0. 005 OP) and Ni-plate (Ni399%)

adding Al

metal Ca

Ni-Mg for deoxidation during vacuum induction smelting

and whole process computer control vacuum consumption remelting speed

the chemical composition of finished products of steel is (% ：)

0. 005 〜0.007C

0. 33 〜0. 34Mn

0. 03 -0. 04Si

0. 001 〜0.002S

0. 004 〜 0. 005P

24. 34 〜24. 62Cr

21. 20 〜21.25Ni to meet the technical requirement

and the oxygen content in steel- (12 ~ 22) x 10

-6

is lower than in steel by ESR process- (30 ~ 80) x 10

-6

.