And Study The Causes Of Related Control Processes Ultra High Strength Stainless Steel Band Structure Analysis

The effect of band that caused by the interdendritic segregation elements in alloy steel, particularly high-alloy steel on mechanical properties, especial the horizontal and vertical anisotropy.is significant. The control and elimination of the band are closely related to solidification environment, hot working and heat treatment process. Focusing on this theme, two types of bande in ultra high strength stainless steel were studied by using the traditional homogenization process, innovative high temperature solution, deformation-induced martensite transformation, and so on.The component analysis of00Cr11Ni11MoTi2maraging stainless steel was acquired by electron probe technology. To determine the type of band, the composition contrast was studied between band and matrix by statistical means. Experiment results showed that the segregation elements in the band were mainly Ni, Cr, Ti, and Ms point of the band was lower than the matrix by20to40℃. The white strip in solution state was retained austenite and residual/reverted austenite in the aging state. The influence of homogenization temperature and time on band in solution and aging states was also studied.,The alloy elements in the segregation band diffused more evenly with higher homogenization temperature and longer insulation time. The homogenization time significantly affected the band distribution after aging. The band could be eliminated under homogenization temperature1200℃with short time3h, but residual austenite would exist after aging. The band could be eliminated completely under homogenization temperature1200℃with long time5h and the reverted austenite would not form in the aging process. The segregation amount of Cr in the band affected the morphology of band after aging..The solution temperature affected the residual of austenite in the process of martensitic transformation, also affected the formation temperature of reversed austenite in the process of aging. With the increasing of solution temperature, the amount of residual/reverted austenite in the state of cooling and aging decreased gradually. And the band was eliminated completely under the solution temperature1000℃with subsequent aging temperatur at480℃and500℃The band in20Cr10Ni6Co14Mo2W ultra-high-strength stainless steel was martensite, and the content of Cr and Mo were lower than that of the matrix by respectively0.76and0.84. Predeformation could induce martensitic phase transformation, the content of martensite increased with more deformation. There was not linear relation between the content of martensite and deformation, and the growth rate of martensite content decreased gradually with the increasing deformation. The effect of aging temperature after the process of predeformation on band was not obvious, when the amount of deformation was less than20%, the increasing rate of microhardness of matrix and martensite band were,almost about50%. when the amount of deformation was more than20%, the microhardness of matrix continued rising, but the microhardness of martensite band increased rapidly.