淬火-分配(Quenching and partitioning,Q&P)钢是淬火和分配复合作用的结果,淬火得到高强度马氏体基体,分配稳定残留奥氏体提高塑性。本工作通过采用具有不同冷速的淬火介质———油、13%PAG和HX-2000淬火,研究了Q&P工艺中淬火...淬火-分配(Quenching and partitioning,Q&P)钢是淬火和分配复合作用的结果,淬火得到高强度马氏体基体,分配稳定残留奥氏体提高塑性。本工作通过采用具有不同冷速的淬火介质———油、13%PAG和HX-2000淬火,研究了Q&P工艺中淬火冷速对中碳钢组织及性能的影响,并探讨了不同分配温度对碳分配过程的影响。结果表明,淬火快速冷却能得到高碳马氏体组织,有利于促进分配过程中马氏体向残留奥氏体的碳扩散,提高碳分配程度,并且随着淬火冷速的增加,马氏体有效晶粒尺寸减小、马氏体组织细化、位错密度增加,从而使中碳钢得到优异的强度和塑性。高温分配能减弱马氏体和残留奥氏体间的碳不均匀性,促进碳从马氏体向残留奥氏体中扩散,起到稳定残留奥氏体的作用,提高中碳钢的断后伸长率。当采用13%PAG淬火、320℃分配时,中碳钢伸长率为10.34%~10.37%,强塑积能达到18.94~19.21 GPa%,表现出更高的强塑性匹配。展开更多
Sulfate and nitrate reducing bacteria are important culprits for microbiologically influenced corrosion(MIC)using sulfate and nitrate as electron acceptors,respectively.Sulfate and nitrate hold different standard elec...Sulfate and nitrate reducing bacteria are important culprits for microbiologically influenced corrosion(MIC)using sulfate and nitrate as electron acceptors,respectively.Sulfate and nitrate hold different standard electrode potentials,which may lead to differences in corrosion,but their effects on corrosion by the same bacteria have not been reported.The corrosion of Q235 steel affected by Pseudodesulfovibrio cashew(P.cashew)in the sulfate and nitrate media under carbon starvation was studied.It was found that sulfate and nitrate did not lead to differences in corrosion under abiotic conditions.However,P.cashew promoted corrosion in both cases,and the consumption of H_(2)was the main mechanism for MIC.In addition,corrosion was more severe in the sulfate media.The higher corrosivity of P.cashew with sulfate as the electron acceptor is closely related to the higher number of sessile cells in the biofilm,higher bacterial motility,more hydrogen production pathways,and the increased gene expression of enzymes related to energy synthesis.展开更多
文摘淬火-分配(Quenching and partitioning,Q&P)钢是淬火和分配复合作用的结果,淬火得到高强度马氏体基体,分配稳定残留奥氏体提高塑性。本工作通过采用具有不同冷速的淬火介质———油、13%PAG和HX-2000淬火,研究了Q&P工艺中淬火冷速对中碳钢组织及性能的影响,并探讨了不同分配温度对碳分配过程的影响。结果表明,淬火快速冷却能得到高碳马氏体组织,有利于促进分配过程中马氏体向残留奥氏体的碳扩散,提高碳分配程度,并且随着淬火冷速的增加,马氏体有效晶粒尺寸减小、马氏体组织细化、位错密度增加,从而使中碳钢得到优异的强度和塑性。高温分配能减弱马氏体和残留奥氏体间的碳不均匀性,促进碳从马氏体向残留奥氏体中扩散,起到稳定残留奥氏体的作用,提高中碳钢的断后伸长率。当采用13%PAG淬火、320℃分配时,中碳钢伸长率为10.34%~10.37%,强塑积能达到18.94~19.21 GPa%,表现出更高的强塑性匹配。
基金Project(2022LSL050102)supported by the Laoshan Laboratory,China。
文摘Sulfate and nitrate reducing bacteria are important culprits for microbiologically influenced corrosion(MIC)using sulfate and nitrate as electron acceptors,respectively.Sulfate and nitrate hold different standard electrode potentials,which may lead to differences in corrosion,but their effects on corrosion by the same bacteria have not been reported.The corrosion of Q235 steel affected by Pseudodesulfovibrio cashew(P.cashew)in the sulfate and nitrate media under carbon starvation was studied.It was found that sulfate and nitrate did not lead to differences in corrosion under abiotic conditions.However,P.cashew promoted corrosion in both cases,and the consumption of H_(2)was the main mechanism for MIC.In addition,corrosion was more severe in the sulfate media.The higher corrosivity of P.cashew with sulfate as the electron acceptor is closely related to the higher number of sessile cells in the biofilm,higher bacterial motility,more hydrogen production pathways,and the increased gene expression of enzymes related to energy synthesis.
