Vitreous and porcelain enamels. Production of specimens for testing enamels on sheet steel, sheet aluminium and cast iron

2011 ◽  
Keyword(s):  
2014 ◽  
Vol 1063 ◽  
pp. 130-142 ◽  
Author(s):  
Hardy Mohrbacher

Martensitic sheet steel is increasingly being used in advanced car body construction, especially in areas where high crash loads are expected. Using such steels appropriately the weight of individual components can be reduced by up to 20 percent. Martensitic steel sheet is commercially available in the strength range of 1200 to 1900 MPa, either as cold forming or hot stamping grade. Whereas the strength of such martensitic steels is practically only a function of the carbon content, other properties such as ductility, toughness, bendability and delayed cracking resistance are severely influenced by other alloying elements and the particular thermal processing route. The paper discusses the influence of various key-alloying elements such as Nb, Mo and B on these properties and suggests routes to optimize the steel’s behavior with respect to the manufacturing and application related aspects.Keywords Martensite, prior austenite grain size, delayed cracking, grain boundary segregation, hydrogen trapping, niobium, molybdenum


2011 ◽  
Vol 221 ◽  
pp. 405-410 ◽  
Author(s):  
Li Liu ◽  
Ti Kun Shan

A relation between the Young’s modulus and the martensitic transformation during TRIP sheet steel stamping is investigated. A TRIP steel, TRIP600, is used to study the phenomenon. The transformation kinetics under different loading paths were gotten through simple-shear, uniaxial tension, plane strain and equibiaxial stretching tests. The Young’s modulus, which plays an important role in accurate springback prediction for TRIP steel sheet stamping, is changed with the martensitic transformation during TRIP steel deformation. To improve the accuracy of springback simulation, the constitutive model of the TRIP steel is developed considering the variation of the Young’s modulus with the martensitic transformation. The accuracy of the proposed method is verified by the experimental results.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261079
Author(s):  
Ziyad Tariq Abdullah

The automobile industry contributes significantly to global energy use and carbon emissions. Hence, there are significant economic and environmental benefits in recovering materials from end-of-life vehicles (ELVs). Here, the remanufacturing of waste steel sheet (WSS) from ELVs into useful mesh steel sheet (MSS) for metal forming applications was evaluated based on its technological, economic, and environmental feasibility. A remanufacturing plant with a dismantling capacity of over 30,171 ELV/year and a recovery capacity of 1000 m2/d of WSS was used as a case study. Remanufacturing can achieve a total reduction of ~3800 kg CO2/ELV and an economic benefit of ~775 USD/ELV compared with conventional recycling. The calculated feasibility indexes were similar to or exceeded standard feasibility thresholds, indicating that WSS remanufacturing is a viable sustainable development route and has synergistic benefits when combined with existing recycling plants, especially in developing countries as small-to-medium enterprises.


Author(s):  
Manel Ellouz ◽  
Eva Kasparek ◽  
Holger Völzke

Up to the end of this decade, corresponding to the planned date of starting operation in the final disposal KONRAD for non-heat generating waste in Germany, a lot of efforts are needed to condition and package the radioactive waste in containers certified by BfS (Federal Institute for Radiation Protection). This waste is produced by public sector and industry as well as nuclear energy facilities, which result in more than a half of the actually declared quantity growing especially after the phase out decision of nuclear power production in Germany and the subsequent decommissioning of nuclear power plants. BAM (Federal Institute for Materials Research and Testing) acts as responsible authority on behalf of BfS for design testing under consideration of the KONRAD requirements. Within the assessment procedure of containers, BAM has to verify the application documents, including material qualification, container geometry, corrosion protection, leakage rate and operational and accidental loading, and to evaluate quality assurance measures. Besides the previous completed approvals for various containers such as steel sheet and cast iron box-shaped containers and concrete cylindrical ones, BAM is actually carrying assessments for other types such as cast iron cylindrical containers and “old” steel sheet box shaped ones. The so called “old” containers present already loaded containers without any KONRAD certification, currently stored at licensed interim storages. In the benefit of the container assessment, BAM operates design testing facilities for drop and fire tests which are also used for research objectives to improve and expand the evaluation methods such as research project ConDrop. The latter deals with numerical simulations and analyses tools for further precise predictions about unfavorable drop test scenarios, safety margins, and design sensitivities for steel sheet containers. Furthermore, during the assessment procedure, several specifications about the containers, the inventory to be disposed and the required safety level have been intensely debated by authorities and applicants. Based on its experience in qualifying containers, BAM has been commissioned to identify insufficiently specified aspects in the waste acceptance criteria and to propose clearer definitions with regard to the secondary regulations in the planning approval notice. This paper focuses on aspects of the contribution of BAM in certifying KONRAD waste containers. This will include the current state of design testing procedures, evaluation methods that are available or are being developed and the main topics within the KONRAD requirements being actually specified by BAM.


2011 ◽  
Vol 239-242 ◽  
pp. 1707-1710 ◽  
Author(s):  
Yan Wen Zhang ◽  
Ji Hui Wang ◽  
Yu Chen

Powdering and desquamation is prone to happen when galvannealed sheet steel is stampinged and Powdering or desquamation often happens at the fragile phase where Fe content is high. The fragile phase thickness of the coating of galvannealed steel sheet is correlative nearly to the coating anti-pulverization ability.So it is very important to measure the fragile phase thickness with the research of galvannealed sheet steel process. The fragile phase thickness of the same batch galvannealed sheet steel made by some steel plant is about 560~590nm when it is measured by glow ischarge spectrometer , fracture observation methods by SEM and metallographic microscope, the error is very little.


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