Kinetic Study of the Nitrogen Reaction With Liquid Third-Generation Advanced High-Strength Steels: Experimental Design and Industrial Significance

Author(s):  
P. Tang ◽  
D. Pistorius
Author(s):  
Tarun Nanda ◽  
Vishal Singh ◽  
Virender Singh ◽  
Arnab Chakraborty ◽  
Sandeep Sharma

The automobile industry is presently focusing on processing of advanced steels with superior strength–ductility combination and lesser weight as compared to conventional high-strength steels. Advanced high-strength steels are a new class of materials to meet the need of high specific strength while maintaining the high formability required for processing, and that too at reasonably low cost. First and second generation of advanced high-strength steels suffered from some limitations. First generation had high strength but low formability while second generation possessed both strength and ductility but was not cost effective. Amongst the different types of advanced high-strength steels grades, dual-phase steels, transformation-induced plasticity steels, and complex phase steels are considered as very good options for being extended into third generation advanced high-strength steels. The present review presents the various processing routes for these grades developed and discussed by different authors. A novel processing route known as quenching and partitioning route is also discussed. The review also discusses the resulting microstructures and mechanical properties achieved under various processing conditions. Finally, the key findings with regards to further research required for the processing of advanced high-strength steels of third generation have been discussed.


Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1051 ◽  
Author(s):  
António B. Pereira ◽  
Rafael O. Santos ◽  
Bruno S. Carvalho ◽  
Marilena C. Butuc ◽  
Gabriela Vincze ◽  
...  

To meet the demands of vehicular safety and greenhouse gas emission reduction, the automotive industry is increasingly using advanced high strength steels (AHSS) in the production of the components. With the development of the new generation of AHSS, it is essential to study their behavior towards manufacturing processes used in the automotive industry. For this purpose, the welding capability of newly developed third-generation Gen3 980T steel was investigated using the Nd:YAG (Neodymium:Yittrium Aluminum Garnet) laser-welding with different parameter conditions. The analysis was made by uniaxial tensile tests, micro-hardness, Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The criteria used to evaluate the quality of the weld were the distance between the fracture and the weld bead and the surface finish. A relationship between the quality of the weld and the energy density was observed, expressed by a partial penetration for values below the optimal, and by irregularities in the weld bead and a high number of spatters for the values above the optimal.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4970
Author(s):  
Jacqueline Noder ◽  
Jon Edward Gutierrez ◽  
Amir Zhumagulov ◽  
James Dykeman ◽  
Hesham Ezzat ◽  
...  

While the third generation of advanced high-strength steels (3rd Gen AHSS) have increasingly gained attention for automotive lightweighting, it remains unclear to what extent the developed methodologies for the conventional dual-phase (DP) steels are applicable to this new class of steels. The present paper provides a comprehensive study on the constitutive, formability, tribology, and fracture behavior of three commercial 3rd Gen AHSS with an ultimate strength level ranging from 980 to 1180 MPa which are contrasted with two DP steels of the same strength levels and the 590R AHSS. The hardening response to large strain levels was determined experimentally using tensile and shear tests and then evaluated in 3D simulations of tensile tests. In general, the strain rate sensitivity of the two 3rd Gen 1180 AHSS was significantly different as one grade exhibited larger transformation-induced behavior. The in-plane formability of the three 1180 MPa steels was similar but with a stark contrast in the local formability whereas the opposite trend was observed for the 3rd Gen 980 and the DP980 steel. The forming limit curves could be accurately predicted using the experimentally measured hardening behavior and the deterministic modified Bressan–Williams through-thickness shear model or the linearized Modified Maximum Force Criterion. The resistance to sliding of the three 3rd Gen AHSS in the Twist Compression Test revealed a comparable coefficient of friction to the 590R except for the electro-galvanized 3rd Gen 1180 V1. An efficient experimental approach to fracture characterization for AHSS was developed that exploits tool contact and bending to obtain fracture strains on the surface of the specimen by suppressing necking. Miniature conical hole expansion, biaxial punch tests, and the VDA 238-100 bend test were performed to construct stress-state dependent fracture loci for use in forming and crash simulations. It is demonstrated that, the 3rd Gen 1180 V2 can potentially replace the DP980 steel in terms of both the global and local formability.


2021 ◽  
Vol 11 (4) ◽  
pp. 241-247
Author(s):  
Meknassi Raid Fekhreddine ◽  
Miklós Tisza

The modern vehicles demand a better fuel economy, decrease in ozone harming substance outflows, and superior safety requirements led to new developments of steel grades with higher strength and good formability. Third generation of advanced high strength steels are the next stage for the automotive companies in steel sheets development. The principal concept of third generation of AHSS is to reap the mechanical properties benefits from first and second generation of AHSS at cost neither too high nor too low. This literature review summarizes the results achieved in a previous paper of the Third Generation of Advanced High Strength Sheet steels literature published by D. Krizan et al. Where we intend to focus on, the recent developments and future trends of the third generation of advanced high strength sheet steels (3-GEN AHSSs) including quenching and partitioning (Q&P), TRIP bainitic ferrite (TBF), medium manganese, density reduced TRIP (δ-TRIP) and nano steels for the modern automotive industry, with emphasis on their main characteristics, processing, and applications.


Sign in / Sign up

Export Citation Format

Share Document