检索结果-南通市图书馆

Thermal and chemical analysis of massive use of hot briquetted iron inside basic oxygen furnace

在线全文

学校读者我要写书评

暂无评论

引用

Journal of Iron and Steel Research International 2017年第9期24卷 901-907页

作者： Cosmo Di Cecca Silvia Barella carlo mapelli Andrea Gruttadauria Andrea Francesco Ciuffini Davide Mombelli Enrico Bondi Depatment of Mechanical Engineering Politecnico di MilanoMilano 20156Italy Freelance Milano 20100Italy

The integrated steelmaking cycle based on the blast furnace-basic oxygen furnace（BOF）route plays an important role in the production of plain and ultra-low carbon steel,especially for deep drawing *** steelmaking is based on the conversion of cast iron in steel by impinging oxygen on the metal bath at supersonic *** order to avoid the addition of detrimental chemical elements owing to the introduction of uncontrolled scrap and in order to decrease environmental impact caused by the intensive use of coke for the production of cast iron,HBI（hot briquetted iron）can be used as a source of metal and a fraction of cast *** industrial experimental tests were performed to evaluate the viability of the use of HBI in *** experimental campaign was supported by a thermal prediction model and realized through the estimation of the oxidation ***,the process was thermodynamically analyzed based on oxygen potentials using the off-gas composition and the bath temperature evolution during the conversion as reference data.

关键词： Hot briquetted iron Basic oxygen furnace Thermal analysis Chemical analysis Oxygen potential

Dynamic Recrystallization Behavior of Q370qE Bridge Steel

在线全文

学校读者我要写书评

暂无评论

引用

Chinese Journal of Mechanical Engineering 2023年第5期36卷 330-340页

作者： Caiyi Liu Shicheng Liang Yan Peng Jianliang Sun carlo mapelli Silvia Barella Andrea Gruttadauria Marco Belf Ludovica Rovatti National Engineering Research Center for Equipment and Technology of Cold Roll Strip Rolling Yanshan UniversityQinhuangdao 066004China Department of Mechanical Engineering Politecnico di Milano20156 MilanItaly

Bridge steel has been widely used in recent years for its excellent performance. Understanding the high-temperature Dynamic Recrystallization (DRX) behavior of high-performance bridge steel plays an important role in guiding the thermomechanical processing process. In the present study, the hot deformation behavior of Q370qE bridge steel was investigated by hot compression tests conducted on a Gleeble 3800-GTC thermal-mechanical physical simulation system at temperatures ranging from 900 ℃ to 1100 ℃ and strain rates ranging from 0.01 s^(−1) to 10 s^(−1). The obtained results were used to plot the true stress-strain and work-hardening rate curves of the experimental steel, with the latter curves used to determine the critical strains for the initiation of DRX. The Zener-Hollomon equation was subsequently applied to establish the correspondence between temperature and strain rate during the high-temperature plastic deformation of bridge steel. In terms of the DRX volume fraction solution, a new method for establishing DRX volume fraction was proposed based on two theoretical models. The good weathering and corrosion resistance of bridge steel lead to difculties in microstructure etching. To solve this, the MTEX technology was used to further develop EBSD data to characterize the original microstructure of Q370qE bridge steel. This paper lays the theoretical foundation for studying the DRX behavior of Q370qE bridge steel.

关键词： Dynamic recrystallization Materials characterization Hot deformation DRX volume fraction model

Solidification microstructure of centrifugally cast Inconel 625

在线全文

学校读者我要写书评

暂无评论

引用

China Foundry 2017年第4期14卷 304-312页

作者： Silvia Barella Andrea Gruttadauria carlo mapelli Davide Mombelli Paolo Taiana Matteo Bosatra Alberto Morini Dipartimento di Meccanica Politecnico di Milanovia La Masa 120156 MilanoItaly Fondinox via Marconi 42/4826010 Sergnano(CR)Italy

Centrifugal casting is a foundry process allowing the production of near net-shaped axially symmetrical components. The present study focuses on the microstructural characterization of centrifugally cast alloys featuring different chemical compositions for the construction of spheres applied in valves made of alloy IN625 for operation at high pressure. Control of the solidification microstructure is needed to assure the reliability of the castings. Actually, a Ni-base superalloy such as this one should have an outstanding combination of mechanical properties, high temperature stability and corrosion resistance. Alloys such as IN625 are characterised by a large amount of alloying elements and a wide solidification range, so they can be affected by micro-porosity defects, related to the shrinkage difference between the matrix and the secondary reinforcing phases(Nb-rich carbides and Laves phase). In this study, the microstructure characterization was performed as a function of the applied heat treatments and it was coupled with a calorimetric analysis in order to understand the mechanism ruling the formation of micro-porosities that can assure alloy soundness. The obtained results show that the presence of micro-porosities is governed by morphology and by the size of the secondary phases, and the presence of the observed secondary phases is detrimental to corrosion resistance.

关键词： alloy IN625 centrifugal casting solidification defects Nb carbides Laves phases micro-porosity corrosion