The effects of boron contents on the solution time and temperature of precipitated phase in steel S31254 are studied by solution treatment. The time and temperature required for the complete solution of steel S31254 second phase under different boron contents are obtained. The results show that as the boron content increases

the required solid solution temperature and time decrease. When the boron content in the steel is 0.002%

a relatively pure austenite structure can be obtained by solid solution treatment at 1200℃ for 4 hours

that is to say

the second phases precipitated in the grains and grain boundary have been re-dissolved into the matrix during the hot working process. In addition

during the solid solution treatment

the second phases in the grains preferentially dissolve

and as passage of time

the second phases at the grain boundary gradually dissolve.