介绍了10Cr21Mn16NiN钢线材成分设计、增氮原理、冶炼工艺、轧制和固溶工艺、Cr_(2)N相析出的生产工艺。采用30 t AOD精炼,吹氮气增氮,精炼后期加氮化锰。轧制时采用1240℃加热、控轧控冷,保证了盘条表面质量,避免了中心缩孔等问题;固...介绍了10Cr21Mn16NiN钢线材成分设计、增氮原理、冶炼工艺、轧制和固溶工艺、Cr_(2)N相析出的生产工艺。采用30 t AOD精炼,吹氮气增氮,精炼后期加氮化锰。轧制时采用1240℃加热、控轧控冷,保证了盘条表面质量,避免了中心缩孔等问题;固溶温度应控制在1100℃左右,且保温30 min后快冷,可防止Cr_(2)N相析出。成功生产出表面质量和性能优良的10Cr21Mn16NiN不锈钢线材。展开更多
Aiming at serious catastrophic oxidation problem of super-austenitic stainless steel S32654,the influence of different rare earth elements on its oxidation behavior was comparatively investigated at 1200℃.The mechani...Aiming at serious catastrophic oxidation problem of super-austenitic stainless steel S32654,the influence of different rare earth elements on its oxidation behavior was comparatively investigated at 1200℃.The mechanism of Y significantly improving high-temperature oxidation resistance of S32654 was unveiled.The results demonstrated that Y played much better beneficial roles than Ce and La in the initial formation of oxide layer:(1)Y promoted Cr segregation to steel surface to combine with O;(2)its preferential oxidation provided nucleation cores for Cr_(2)O_(3).Both roles jointly promoted the selective oxidation of Cr and then the formation of protective Cr-rich oxide layer.This provided good prerequisites for inhibiting the formation and volatilization of MoO_(3).Additionally,Y cation segregation to oxide grain boundaries further promoted the selective oxidation of Cr and Si to form more protective oxide layer.These beneficial roles of Y essentially eliminated the synergistic effects of MoO_(3) volatilization and lamellar Cr_(2)N precipitation on catastrophic oxidation.Accordingly,the oxidation resistance of Y-bearing S32654 was improved by 22%–45%.展开更多
Precipitation behavior of P550 steel for non-magnetic drill collars was investigated by microstructure characterization as well as thermodynamic calculation.The results demonstrate that the main precipitate formed at ...Precipitation behavior of P550 steel for non-magnetic drill collars was investigated by microstructure characterization as well as thermodynamic calculation.The results demonstrate that the main precipitate formed at 650–900℃was cellular Cr_(2)N,and its precipitation depended heavily on the aging temperature.The most sensitive precipitation temperature of cellular Cr_(2)N was 750℃.At 750℃,the cellular Cr_(2)N exhibited fast-slow precipitation kinetics with the aging time prolonging.The initial precipitation of cellular Cr_(2)N was governed by the short-range intergranular diffusion of Cr.During long-term aging,its growth was controlled by the long-range bulk diffusion of Cr.In addition,cellular Cr_(2)N induced the precipitation of r phase ahead of the cell after long period of aging.Increasing the nitrogen content resulted in the increment of both the nucleation site and the driving force for the cellular Cr_(2)N,which jointly promoted its precipitation.展开更多
文摘介绍了10Cr21Mn16NiN钢线材成分设计、增氮原理、冶炼工艺、轧制和固溶工艺、Cr_(2)N相析出的生产工艺。采用30 t AOD精炼,吹氮气增氮,精炼后期加氮化锰。轧制时采用1240℃加热、控轧控冷,保证了盘条表面质量,避免了中心缩孔等问题;固溶温度应控制在1100℃左右,且保温30 min后快冷,可防止Cr_(2)N相析出。成功生产出表面质量和性能优良的10Cr21Mn16NiN不锈钢线材。
基金the National Natural Science Foundation of China(Nos.U1860204 and 52004061)the Talent Project of Revitalizing Liaoning(No.XLYC1802101)+2 种基金the China Postdoctoral Science Foundation(No.2020M670777)the Northeastern University Postdoctoral Funds(No.20200321)the Fundamental Research Funds for the Central Universities(No.N2125017)。
文摘Aiming at serious catastrophic oxidation problem of super-austenitic stainless steel S32654,the influence of different rare earth elements on its oxidation behavior was comparatively investigated at 1200℃.The mechanism of Y significantly improving high-temperature oxidation resistance of S32654 was unveiled.The results demonstrated that Y played much better beneficial roles than Ce and La in the initial formation of oxide layer:(1)Y promoted Cr segregation to steel surface to combine with O;(2)its preferential oxidation provided nucleation cores for Cr_(2)O_(3).Both roles jointly promoted the selective oxidation of Cr and then the formation of protective Cr-rich oxide layer.This provided good prerequisites for inhibiting the formation and volatilization of MoO_(3).Additionally,Y cation segregation to oxide grain boundaries further promoted the selective oxidation of Cr and Si to form more protective oxide layer.These beneficial roles of Y essentially eliminated the synergistic effects of MoO_(3) volatilization and lamellar Cr_(2)N precipitation on catastrophic oxidation.Accordingly,the oxidation resistance of Y-bearing S32654 was improved by 22%–45%.
基金the National Natural Science Foundation of China(Grant Nos.U1960203 and 51774074)Shanxi Municipal Major Science&Technology Project(Grant No.20181101014)+2 种基金Fundamental Research Funds for the Central Universities(Grant Nos.N172512033 and N2024005-4)Talent Project of Revitalizing Liaoning(XLYC1902046)State Key Laboratory of Metal Material for Marine Equipment and Application(Grant No.HG-SKL(2019)13).
文摘Precipitation behavior of P550 steel for non-magnetic drill collars was investigated by microstructure characterization as well as thermodynamic calculation.The results demonstrate that the main precipitate formed at 650–900℃was cellular Cr_(2)N,and its precipitation depended heavily on the aging temperature.The most sensitive precipitation temperature of cellular Cr_(2)N was 750℃.At 750℃,the cellular Cr_(2)N exhibited fast-slow precipitation kinetics with the aging time prolonging.The initial precipitation of cellular Cr_(2)N was governed by the short-range intergranular diffusion of Cr.During long-term aging,its growth was controlled by the long-range bulk diffusion of Cr.In addition,cellular Cr_(2)N induced the precipitation of r phase ahead of the cell after long period of aging.Increasing the nitrogen content resulted in the increment of both the nucleation site and the driving force for the cellular Cr_(2)N,which jointly promoted its precipitation.
