This paper deals with indirect effects of major impacting throughout the Early Paleozoic resp. with those of super plume activity during the Early Cretaceous, both applied to the siliciclastic series of Jordan deposit...This paper deals with indirect effects of major impacting throughout the Early Paleozoic resp. with those of super plume activity during the Early Cretaceous, both applied to the siliciclastic series of Jordan deposited on the Arabian Platform, Arabian Plate. Its focus is mainly directed on gases released by both processes (CO2, SO2, NOx, HCl, HF) and the relating acids, challenged by experiments and microscopic analysis of grain mounts and thin sections that reveal chemical instability of quartz and ultrastable heavy minerals (i.e. tourmaline) under high acidity (pH °C - 90°C). According to Lopatin’s Time/Temperatur-Index the Lower Cambrian reached the onset of hydrocarbon generation (liquid window) during the Lower Early Cretaceous. Unstable heavy minerals (apatite, garnet, hornblende, epidote, zoisite/clinozoisite) are generally absent in quartz arenites while in arkosic sandstones of marine environment carbonate cement and primary clay minerals (illite) provide conservation. As known since the eighties, the K/T-event’s indirect effects had global influence on Earth’s surface sediments and atmospheric chemistry by wildfires, hot whirl storms, acidic “sturz rain”, dust, soot, darkness, loss of photosynthesis, toxic metals, gases and relating acids. All of them are here concerned and applied to major impacting throughout the Early Paleozoic using the impact data of Price (2001);while superplume volcanism during Cretaceous led to the opening of the South Atlantic accompanied by the cyclic outflow of the Para?a/Etendeka Flood Basalts and relating gases in a gigantic scale (137 - 127 Ma). Assuming that the gases cause similar global effects on Earth’s surface sediments, an according result may be expected in form of quartz arenites and their sequence-analytical patterns (cyclic SBs, MFSs).*展开更多
The nose temperature for σ-phase precipitation in super-duplex stainless steel （SDSS） UNS S32750 was evaluated by hardness method.Color-optical microscopy,scanning electron microscopy,energy spectrum analysis,impac...The nose temperature for σ-phase precipitation in super-duplex stainless steel （SDSS） UNS S32750 was evaluated by hardness method.Color-optical microscopy,scanning electron microscopy,energy spectrum analysis,impact and corrosion testing were carried out to investigate characteristics of microstructure and properties of the SDSS aged at the nose temperature.The experimental results indicate that the nose temperature of precipitation is 920℃ and aging at this temperature tiny σ phases can precipitate at phase interfaces or ferrite grain boundaries within 2min.Prolonging aging duration the amount ofσ-phase increases and a dual structure with σ and γ is obtained when aging for 120min.The precipitation ofσ-phase leads to severe deterioration in impact toughness （longitudinal/transverse direction） and corrosion resistance of SDSS.展开更多
以UNS S32750超级双相不锈钢为研究对象,采用冷金属过渡脉冲(cold metal transfer pulse,CMT-P)复合电弧焊接技术,运用光学显微镜、扫描电子显微镜、透射电子显微镜、X射线衍射仪和电子探针组织表征手段以及显微硬度和低温冲击韧性性能...以UNS S32750超级双相不锈钢为研究对象,采用冷金属过渡脉冲(cold metal transfer pulse,CMT-P)复合电弧焊接技术,运用光学显微镜、扫描电子显微镜、透射电子显微镜、X射线衍射仪和电子探针组织表征手段以及显微硬度和低温冲击韧性性能测试方法,对比研究了纯Ar和Ar+2%N_(2)气体保护对焊接接头的微观组织、硬度和低温韧性的影响规律.结果表明,与纯Ar保护气相比,添加2%N_(2)保护的焊接过程飞溅较少,焊缝平整笔直,鱼鳞纹更加细致紧密.此外,热影响区主要由过量的铁素体和少量的奥氏体组成,并伴随有害的Cr2N析出.因此,与CMT-P复合电弧焊接头的其它区域相比,热影响区的硬度较高和韧性较低.添加2%N_(2)气体保护增加了焊缝和热影响区奥氏体含量和N原子在铁素体与奥氏体内的固溶量,从而提高了接头各区域的低温韧性.展开更多
文摘This paper deals with indirect effects of major impacting throughout the Early Paleozoic resp. with those of super plume activity during the Early Cretaceous, both applied to the siliciclastic series of Jordan deposited on the Arabian Platform, Arabian Plate. Its focus is mainly directed on gases released by both processes (CO2, SO2, NOx, HCl, HF) and the relating acids, challenged by experiments and microscopic analysis of grain mounts and thin sections that reveal chemical instability of quartz and ultrastable heavy minerals (i.e. tourmaline) under high acidity (pH °C - 90°C). According to Lopatin’s Time/Temperatur-Index the Lower Cambrian reached the onset of hydrocarbon generation (liquid window) during the Lower Early Cretaceous. Unstable heavy minerals (apatite, garnet, hornblende, epidote, zoisite/clinozoisite) are generally absent in quartz arenites while in arkosic sandstones of marine environment carbonate cement and primary clay minerals (illite) provide conservation. As known since the eighties, the K/T-event’s indirect effects had global influence on Earth’s surface sediments and atmospheric chemistry by wildfires, hot whirl storms, acidic “sturz rain”, dust, soot, darkness, loss of photosynthesis, toxic metals, gases and relating acids. All of them are here concerned and applied to major impacting throughout the Early Paleozoic using the impact data of Price (2001);while superplume volcanism during Cretaceous led to the opening of the South Atlantic accompanied by the cyclic outflow of the Para?a/Etendeka Flood Basalts and relating gases in a gigantic scale (137 - 127 Ma). Assuming that the gases cause similar global effects on Earth’s surface sediments, an according result may be expected in form of quartz arenites and their sequence-analytical patterns (cyclic SBs, MFSs).*
基金Founded by the Special Project of Shaanxi Education Department(07JK309)Xi'an University of Architecture and Technology (JC0714)
文摘The nose temperature for σ-phase precipitation in super-duplex stainless steel （SDSS） UNS S32750 was evaluated by hardness method.Color-optical microscopy,scanning electron microscopy,energy spectrum analysis,impact and corrosion testing were carried out to investigate characteristics of microstructure and properties of the SDSS aged at the nose temperature.The experimental results indicate that the nose temperature of precipitation is 920℃ and aging at this temperature tiny σ phases can precipitate at phase interfaces or ferrite grain boundaries within 2min.Prolonging aging duration the amount ofσ-phase increases and a dual structure with σ and γ is obtained when aging for 120min.The precipitation ofσ-phase leads to severe deterioration in impact toughness （longitudinal/transverse direction） and corrosion resistance of SDSS.
文摘以UNS S32750超级双相不锈钢为研究对象,采用冷金属过渡脉冲(cold metal transfer pulse,CMT-P)复合电弧焊接技术,运用光学显微镜、扫描电子显微镜、透射电子显微镜、X射线衍射仪和电子探针组织表征手段以及显微硬度和低温冲击韧性性能测试方法,对比研究了纯Ar和Ar+2%N_(2)气体保护对焊接接头的微观组织、硬度和低温韧性的影响规律.结果表明,与纯Ar保护气相比,添加2%N_(2)保护的焊接过程飞溅较少,焊缝平整笔直,鱼鳞纹更加细致紧密.此外,热影响区主要由过量的铁素体和少量的奥氏体组成,并伴随有害的Cr2N析出.因此,与CMT-P复合电弧焊接头的其它区域相比,热影响区的硬度较高和韧性较低.添加2%N_(2)气体保护增加了焊缝和热影响区奥氏体含量和N原子在铁素体与奥氏体内的固溶量,从而提高了接头各区域的低温韧性.
