Understanding the Effect of Aluminum Addition on the Forming of Second Phase Particles on Grain Growth of Micro-Alloyed Steel

Abstract

The formation of second phase particles in the steel matrix during melting and casting plays an important role in controlling the grain size of steel. An attempt is made in the present work to find the role of nitrogen on forming nitride particles either with aluminum or titanium. Two steel samples with the same titanium and aluminum weight percent in their chemical composition were collected after the hot rolling process. Solution heat treatment at 1350°C for 60min holding time was used to dissolve the particles and then the steel samples were reheated at 800°C for 60min, water quenched and their microstructure was revealed by usual grinding and polishing process using 2% Nital. A transmission electron microscope connected with EDS was used to reveal the morphology of the second phase particles. The samples for TEM analysis were prepared by the replica extraction method in 5% Nital solution. The samples were then caught in 3mm copper grid for TEM analysis. TEM micrographs revealed the second phase particles in the matrix of steel. EDS peaks were studied and titanium peaks were found in both samples and surprisingly there was not any peak found for aluminum.

Effect of Aluminum Addition with Nitrogen on K-Carbide Formation in Carbon-Mn Steel

“…Influence of aluminum addition with nitrogen on kcarbide formation in C-Mn steel was investigated. Two steel samples A and B were chosen with and without aluminum in their chemical composition to clearly observe the effect on formation of kappa carbides [10,11]. In steel B the presence of aluminum in conjunction with nitrogen forms the small nitride particles that played a crucial role in formation of k-carbide particles which were distributed the entire matrix and as a result fine grain structure formed 2-theta degree Intensity, counts 2-theta degree Intenisty, counts [1,5,6].…”

Iron-based intermetallic particles formation in Al-Zn-Si alloy through powder metallurgy route

“…The diffraction peaks of iron are gradually shifted to a large angle and appear to be broadened, which means that as the milling time is prolonged, Al and iron diffuse into each other lattice to form AlFe solid solution and eventually Fe-based intermetallic compounds (AlFeSi). AlFe intermetallic phases are commonly observed in steel alloys (Abro et al, 2020).…”

Influence of Heat-Treatment on Microstructural and Mechanical Characteristic of Steel

“…Once the heat treatment process was completed, this Microstructural analyses were carried out using optical microscopes [7,8].…”

“…The microstructure was determined after necessary metallographic steps. Since it plays a fundamental role in determining the workability and mechanical properties of the material [5], all the specimens were etched using a Nital solution (2%). Multiple changes in microstructure were observed after the annealing process.…”

“…For example toughness of the material is enhanced and brittleness is reduced by the annealing process [3]. In contrast, internal stresses are generated by welding, forging and machining [4][5][6]. On the other hand, quenching hardens the material and provides strength to metals.…”