During performance testing of 6200 mm YG1900 ultra-high strength steel produced by 6 t VIM + 6 t VAR double vacuum process smelting + forging material process

the uneven performance is found. In this paper

the scanning electron microscopy and electron probe analysis are carried out on the microstructure of samples with uneven performance

the result shows that the segregation of carbides in structure caused by the segregation of W and Mo is the reason of uneven performance. After conducting a series of measurement by reducing the melting rate of vacuum consumable smelting from 4 ~ 5 kg/min to 3 ~ 4 kg/min

increasing the homogenization temperature of forged steel ingots from I 200 ~ 1 220 °C to 1 230 ~ 1 250 °C

and increasing the total forging ratio of forging production increased from 24 ~ 30 to 50 〜56

the problem of uneven performance of YG1900 ultra-high-strength steel is improved after process improvement.