Precipitation Strengthening by Induction Treatment in High Strength Low Carbon Microalloyed Hot-Rolled Plates

Influence of Finish Rolling Temperature and Molybdenum Addition on Strengthening of Low Carbon Niobium Steels—A Computational and Experimental Study

“…It is important to remember that finer ferrite grain size will also improve toughness, whereas a majority polygonal ferrite matrix will result in better stretch formability. Recent multihit hot plate rolling study by Larzabal et al [7] toward development of bainitic microstructures resulted in average yield strength of 418 and 451 MPa with overall UTS of 523 and 630 MPa for 0.04C-0.03Nb and 0.05C-0.03Nb-0.2Mo steels, respectively, highlighting the influence of Mo in improving both yield strength and UTS. It is, thus, appropriate to claim that with slightly higher C content in NbMo steels can improve yield strength and UTS simultaneously, whereas controlled processing strategies could lead to evolution of precipitation strengthened polygonal ferrite matrix beneficial to thin sheet applications.…”

“…[3][4][5] Several studies have investigated the role of microalloying and TMP routes on the evolution of harder (nonequilibrium) phases as matrix microstructures, such as acicular ferrite, bainite, and martensite, for high-strength plate and pipeline applications. [6][7][8][9][10][11][12][13] However, a harder phase matrix microstructure suffers from poor stretch flangeability (formability) due to its poor local elongation abilities near higher stress concentration zones along the soft/hard interfaces, leading to premature microvoid crack initiation and failure in thin-sheet applications. [14,15] This explains interest in softer equilibrium phases as matrix microstructures such as ferrite.…”

Molybdenum alloying in high-performance flat-rolled steel grades

“…In the first step, bainitic microstructure with fine grain size and high dislocation density is produced by targeting a low cooling-stop temperature. In the second step, the fine-grained bainitic steel is re-heated to a temperature allowing efficient precipitation [19]. It is important in this process sequence that the initially produced bainitic structure with high dislocation density is not being removed by recovery or recrystallization during the subsequent annealing process.…”

Microstructure and precipitates in thick-walled X90 bend related to mechanical properties

“…The composite microstructure of AF and GB ensures that the bend with a good toughness, but the plasticity and large strain resistance is difficult to reach the level of the parent pipeline steel [17,18]. Many literatures [18,20,21] investigated the hot induction bend were focus on the effects of hot bending parameters on microstructure and mechanical properties, and the relationship of microstructure and mechanical properties through thermal simulation tests. However, the deformation in the bending process was not take into account.…”