Mechanical Properties and Microstructural Evolution of Simulated Heat-Affected Zones in Wrought Eglin Steel

Effect of laser reheat post-treatment on the microstructural characteristics of laser-cladded ultra-high strength steel

“…Such an increase in retained austenite will result in a decrease in martensite formation which is beneficial to fracture toughness as reported by Thomas [18]. Similarly, Leister [15] mentions that the retained austenite is considered to be thermally stable and the carbides do not precipitate from the solid solution when reheated to a temperature above Ac1. Hebsur [17] mentions that the small amounts of the soft retained austenite phase contributes to about three times more plastic work than the hard martensite phase.…”

“…Other phases such as ferrite, bainite, and cementite may not form in the laser-cladded structure, as laser cladding is a non-equilibrium solidification process with significantly higher cooling rates as compared to the conventional fabrication processes. Leister [15] reported that cooling rates as low as 0.01 -0.2 °C/s are required for the formation of bainite and pearlite for quench and tempered steel. Likewise, Spanos et al [16] found that the cementite present in the as-received HSLA-100 steel dissolves in the martensite matrix when subjected to elevated temperature processing such as welding.…”

“…The HAZ region close to the clad-HAZ interface experienced a temperature higher than Ac1 but below Ac3, resulting in coarsening (CGHAZ) as well as tempering of the martensite whereas the region near the HAZ-substrate interface as well as the substrate experiences temperatures lower than Ac1 and closer to Ms, thereby resulting in little-to-no phase transformation. Leister [15] mentioned that the CGHAZ of quenched and tempered steels possesses the lowest toughness. However, the presence of CGHAZ along with FGHAZ in LPHT cladded samples may be beneficial in improving the toughness of the HAZ of the repaired section.…”

Heuristic Design of Advanced Martensitic Steels That Are Highly Resistant to Hydrogen Embrittlement by ε-Carbide

“…The steel has strength levels like AerMet100, AF1410, and HP9-4-30 but is produced at a reduced cost because of the reduction or elimination of expensive alloying elements, such as nickel and cobalt. A comprehensive study followed to correlate the mechanical properties and microstructural evolution in the heat-affected zone of the Eglin steel [14]. ε-carbide particles were found in an autotempered lath of martensite in the coarse grains of the heat-affected zone (HAZ) of Eglin steel.…”

“…Abrahams (author in [14]) invented a "low alloy high performance steel". The patent application was filed in 2016 and patented in the United States in 2019 [15].…”