CCT curves of Mn-Si steels with different manganese contents or carbon contents were determined. The results show that the transformation range of bainite can be separated from that of ferrite when the manganese conte...CCT curves of Mn-Si steels with different manganese contents or carbon contents were determined. The results show that the transformation range of bainite can be separated from that of ferrite when the manganese content approaches a certain content, and the incubation period of ferrite increases more significantly than that of bainite transformation with the increase of carbon content in Mn-Si steels. Furthermore, water-cooled bainitic steels without adding expensive alloying element were developed. Granular bainite was obtained when a bar with diameter of 300 mm was cooled by water, and a mixed microstructure of granular bainite and martensite was obtained in watercooled plate with thickness of 40 mm. The developed water-cooled bainitic Steels containing no expensive alloying element showed a good combination of strength and toughness. The tensile strength, yield strength, and toughness （AKU at --20℃ ） of bar with diameter of 300 mm after water cooling were higher than 850 MPa, 620 MPa, and 65 J, respectively, and those of plate with thickness of 40mm after water cooling were higher than 1000 MPa, 800 MPa, and 50J, respectively.展开更多
Mn-Si-MEL zeolite was developed as a bi-functional adsorption-catalytic oxidation material for volatile organic compounds(VOCs)elimination due to its good hydrophobicity&good organophileproperty brought by the sub...Mn-Si-MEL zeolite was developed as a bi-functional adsorption-catalytic oxidation material for volatile organic compounds(VOCs)elimination due to its good hydrophobicity&good organophileproperty brought by the substitution of Mn for Al in zeolite and the superior catalytic oxidation property endowed by the existence of Mn species.Various Mn-Si-MEL samples were obtained by introducing Mn to MEL crystallization system via different ways.It was found the incorporated Mn ways have a significant effect on the behavior of Mn being involved in the crystallization of MEL and finally influenced the distribution of Mn in zeolite as well the physicochemical properties of product zeolite.The seeding method(MnS2(Seed))is favorable for the good incorporation and uniform distribution of Mn in zeolite while both recrystallization method(Mn-S2(RC))and direct synthesis method(Mn-S2(DH))are favorable for obtaining more reducible Mn species and surface adsorbed oxygen species.The Mn amount incorporated into zeolite follows Mn-S2(RC)(1.96 wt%)>Mn-S2(Seed)(1.07 wt%)≈Mn-S2(DH)(0.97 wt%),the adsorption capacity of various samples follows Mn-S2(Seed)(83.3μmol/g)≈Mn-S2(RC)(82.1μmol/g)>Mn-S2(DH)(76.1μmol/g),while the catalytic oxidation ability of three samples follows Mn-S2(RC)≈Mn-S2(DH)>Mn-S2(Seed).Furthermore,Mn-S2(RC)which exhibits both superior adsorption capacity and catalytic oxidation ability shows good hydrophobicity and superior recyclability,demonstrating its great potential to be applied in the VOCs elimination by an enrichment-degradation route.展开更多
通过弯曲法测量、热循环训练、扫描电镜、X射线衍射等方法,研究了复合稀土对Fe Mn Si Ni C合金形状记忆效应的影响。研究结果表明,Fe Mn Si Ni C合金中加入复合稀土,能够明显细化合金的金相组织,显著提高合金的形状记忆效应,并使合金表...通过弯曲法测量、热循环训练、扫描电镜、X射线衍射等方法,研究了复合稀土对Fe Mn Si Ni C合金形状记忆效应的影响。研究结果表明,Fe Mn Si Ni C合金中加入复合稀土,能够明显细化合金的金相组织,显著提高合金的形状记忆效应,并使合金表现出微弱的双程记忆效应。试验结果还表明,第一种训练途径以及加入微量复合稀土是降低应力诱发ε马氏体稳定化行之有效的方法,X射线衍射结果表明,该训练方法有助于提高合金中ε→γ转变的ε逆转变率,对提高合金的记忆性能起积极的作用。展开更多
基金Item Sponsored by National High Technology Research and Development Program("863"Program) of China (2007AA03Z511)
文摘CCT curves of Mn-Si steels with different manganese contents or carbon contents were determined. The results show that the transformation range of bainite can be separated from that of ferrite when the manganese content approaches a certain content, and the incubation period of ferrite increases more significantly than that of bainite transformation with the increase of carbon content in Mn-Si steels. Furthermore, water-cooled bainitic steels without adding expensive alloying element were developed. Granular bainite was obtained when a bar with diameter of 300 mm was cooled by water, and a mixed microstructure of granular bainite and martensite was obtained in watercooled plate with thickness of 40 mm. The developed water-cooled bainitic Steels containing no expensive alloying element showed a good combination of strength and toughness. The tensile strength, yield strength, and toughness （AKU at --20℃ ） of bar with diameter of 300 mm after water cooling were higher than 850 MPa, 620 MPa, and 65 J, respectively, and those of plate with thickness of 40mm after water cooling were higher than 1000 MPa, 800 MPa, and 50J, respectively.
基金the finance supported by the Opening Fund of State Key Laboratory of Heavy Oil Processing(No.SKLOP202002001)the Program for Fundamental Research Funds for the Central Universities(No.FRF-AT-20-12)National Natural Science Foundation of China(No.U20A20130).
文摘Mn-Si-MEL zeolite was developed as a bi-functional adsorption-catalytic oxidation material for volatile organic compounds(VOCs)elimination due to its good hydrophobicity&good organophileproperty brought by the substitution of Mn for Al in zeolite and the superior catalytic oxidation property endowed by the existence of Mn species.Various Mn-Si-MEL samples were obtained by introducing Mn to MEL crystallization system via different ways.It was found the incorporated Mn ways have a significant effect on the behavior of Mn being involved in the crystallization of MEL and finally influenced the distribution of Mn in zeolite as well the physicochemical properties of product zeolite.The seeding method(MnS2(Seed))is favorable for the good incorporation and uniform distribution of Mn in zeolite while both recrystallization method(Mn-S2(RC))and direct synthesis method(Mn-S2(DH))are favorable for obtaining more reducible Mn species and surface adsorbed oxygen species.The Mn amount incorporated into zeolite follows Mn-S2(RC)(1.96 wt%)>Mn-S2(Seed)(1.07 wt%)≈Mn-S2(DH)(0.97 wt%),the adsorption capacity of various samples follows Mn-S2(Seed)(83.3μmol/g)≈Mn-S2(RC)(82.1μmol/g)>Mn-S2(DH)(76.1μmol/g),while the catalytic oxidation ability of three samples follows Mn-S2(RC)≈Mn-S2(DH)>Mn-S2(Seed).Furthermore,Mn-S2(RC)which exhibits both superior adsorption capacity and catalytic oxidation ability shows good hydrophobicity and superior recyclability,demonstrating its great potential to be applied in the VOCs elimination by an enrichment-degradation route.
文摘通过弯曲法测量、热循环训练、扫描电镜、X射线衍射等方法,研究了复合稀土对Fe Mn Si Ni C合金形状记忆效应的影响。研究结果表明,Fe Mn Si Ni C合金中加入复合稀土,能够明显细化合金的金相组织,显著提高合金的形状记忆效应,并使合金表现出微弱的双程记忆效应。试验结果还表明,第一种训练途径以及加入微量复合稀土是降低应力诱发ε马氏体稳定化行之有效的方法,X射线衍射结果表明,该训练方法有助于提高合金中ε→γ转变的ε逆转变率,对提高合金的记忆性能起积极的作用。
