Periodic Reporting for period 1 - HIPERMAT (Advanced design, monitoring , development and validation of novel HIgh PERformance MATerials and components)
Reporting period: 2020-11-01 to 2022-04-30
Main backbone of hot stamping process is the austenitizing furnace.. This equipment works under fluctuating high temperature conditions in the entrance of the furnace (from 450 to 750ºC), high loads due to the own weight of beams and the charge, corrosive environments due to the combustion gases, and continuous high temperature inside the furnace, in the range of 930-970ºC. Under those conditions, failure modes are thermal fatigue of beams at the entrance of the furnace, combined corrosion and creep of the inside beams and combined corrosion, creep and wear of rings.
Beams and rings are manufactured by conventional ferrous foundry and steel making processes: beams by steel sand casting and rings by centrifugal casting. Materials commonly used are refractory stainless steels under ASTM A297 or A351 standards, reporting good high temperature mechanical properties such as high temperature yield strength, wear, thermal fatigue, creep resistance, crack propagation rate and corrosion in different environments. However, they present an uneven in-service behavior due to big tolerances ranges in the case of chemical composition for primary, secondary, and residual chemical elements, local(surface) degradation of the component rendering in a prompt failure, lack of tight definition of process variables affecting microstructure and segregations, limitations in process performance to achieve the most adequate microstructure and linked properties.
HIPERMAT project aims at facing these challenges by the development of a modelling architecture that will allow to fix the most adequate chemical composition ranges for each specific use case allowing the introduction of alternative chemical elements to enhance their performance.the introduction of alternative protective coatings,the implementation of Artificial Intelligence (AI) represented in product and process variables advance analyticsand .Development of alternative manufacturing processes of beams and rings that can offer a combination of a sustainability and microstructural transformation to achieve advanced performance properties and reduce environmental impact.
This first analysis of failure mode of components has allowed to fix the basis for performing an adequate selection of the bulk materials for beams and rings manufacturing and materials for ceramic and LMD coatings application. Material selection has been supported in bibliography and thermodynamics-based modelling using CALPHAD simulation technologies.
Constructive and operational data of the furnace has allowed to define the type of sensors and their location in the furnace as well as the generation of a digital twin by physics-based modelling to evaluate the virtual performance of the furnace subjected to future changes.
Test samples corresponding to the different and alternative bulk materials under analysis have been manufactured in the form of keelblocks. Microstructure analysis and testing of mechanical properties such as stress to rupture, creep, thermal fatigue, crack growth rate and wear have been carried out, and selection of more promising materials is in progress.
Substrate samples for LMD application have been manufactured in refractory stainless steel. Commercial superalloy powders have been bought and used for layers generation and for the HEA application as it was not available in the market, melting of a prealloyed material has been done followed by its atomization and powder generation in the required ranges.
Setting up of the LMD process is on-going supported in simulation added by the introduction of material parameters calculated using CALPHAD, significant advances have been made for superalloys and HEA over samples at lab level. Ceramic application over component like geometries is also progressing modifying slurry parameters and ceramic particles configuration to achieve the metallic matrix infiltrated with ceramic particles with similar thermal expansion coefficient as the base metal.
Finally different type of sensors (RTD and thermocouple based) have been printed over ceramic beams and different configuration of adhesion layers and protective layers have been tested, Stability in measuring for RTD sensors have been achieved at lab level and also trials with thermocouple type sensors are progressing.
In terms of environmental and societal impacts HIPERMAT is going to support the sustainable development of the hot stamping technology resulting in lower weight components for the vehicle. The reduction of the weight of transport vehicles is one fundamental way to reduce the energy consumption and thus CO2 emissions caused by transport vehicles. In fact, reducing the weight of a vehicle by just 10 percent can improve its fuel economy by 6 to 8 percent,