Quality Improvement of Continuously Cast Stainless Steel Blooms through Electromagnetic Stirring

Abstract

SynopsisElectromaglletic stirring was ajJjJiied 10 improve the qualities oj conlilll/ousty cast stainless steel blooms Jor seamless tubes. II has beell showlI Ihat (I) Grain refinem ent oj cast struclure qj blooms is obtailled by the stirring. Th e tendency Jar equiaxed crystals to grow becomes jJrolloUlI.ced ill the ascending order oj SUS316, S US 321. S US304 and S US4 30. (2) White bands, negative segregation bands oj solutes, are Jormed ill the stirred blooms. N egative segregation oj solutes at the white band illcreases its intensity in proportion to equilibrium partition co'!/Jiciellt oj solutes. (3) Center cavities in blooms are cOllver ted illto disjJersed porolls Jorm Jrom jJipe Jorm and the star cracks disappear by the stirring. (4) A homogeneous distribution oj o:ferrite in SCS304 blooms alld a refillement oJ Ti (CN) clusters ill Sr..;S321 bloOlllJ are obtained by the stirrillg.

Macrosegregation in strand cast steel: Computation of concentration profiles with a diffusion model

“…Then it is easyto calculate new enthalpyand new average concentrations at time t + At usingexplicitfinitedifference formulations of equations (2) and (4).…”

“…Note that both equations (2) and (4) are validin all three zonesof solid,mushyand liquid.Thenext stepis tocomputethenewliquid fraction.…”

“…Their technique and the present numerical method are closelyrelated. (2) For the completestatement ofthe problem, initialand boundary conditionshave to be prescribed.…”