Effects of microstructural change on fracture characteristics in coarse-grained heat-affected zones of QLT-processed 9% Ni steel

Investigation of the evolution of retained austenite in Fe–13%Cr–4%Ni martensitic stainless steel during intercritical tempering

“…Much effort has been invested to introduce some retained austenite into bainite or martensite steels via well-designed heat treatments, such as quenching-partitioning [1][2][3], quenching, larmellarizing and tempering (QLT) [4][5][6], quenching and modest tempering [7][8][9], and quenching and intercritical tempering [10][11][12][13]. All these heat treatments provide some austenite stabilizing elements an opportunity to segregate into austenite grains, enhancing the austenite stability and retaining some or all austenite grains formed at high temperature at room temperature without decomposition.…”

Effect of Controlled Cooling on Microstructure and Tensile Properties of Low C Nb-Ti-Containing HSLA Steel for Construction

“…Extensive investigations [2,[6][7][8] have indicated that an appropriate dual-phase microstructure containing granular bainitic ferrite (GBF) and/or quasi-polygonal ferrite (QPF) and M/A constituent is essential to balance the above described yield strength and YR in plate steel produced by TMCP. An increased amount of M/A constituent acting as a mixed hard phase [9][10][11][12] can enhance the stain-hardening capacity of the soft ferrite Round bar specimens with length × diameter of Φ 75 × 15 mm were cut from the plates, and thermo-mechanically processed using a Gleeble 3500 system; the process routings are shown schematically in Figure 1. A group of specimens was produced by diffusion annealing at 1180 • C for 10 min, compressing at 1080 • C for a strain of 0.35 to simulate rough rolling, subsequently compressing at 830 • C for a strain of 0.30 to simulate finish rolling, and finally controlled cooling.…”

“…The controlled cooling processes were conducted with commencing at 780 • C, cooling to 450 • C at four different rates of 5-20 • C/s, re-reddening up to 500 • C for promoting the carbon atom diffusion from α to metastable austenite (γ ), and air-cooling to room temperature. constituent acting as a mixed hard phase [9][10][11][12] can enhance the stain-hardening capacity of the soft ferrite phase [2,[6][7][8]13] and correspondingly lower the YR, which has been achieved by the addition of nitrogen to V-microalloyed steel [8], and the accelerated cooling followed by heat-treatment on-line process (HOP) of Nb-microalloyed steel [6,7]. Nevertheless, the M/A constituent acting as brittle islands can cause a toughness loss [14][15][16], which can be prevented by grain refinement of soft ferrite phase [17].…”

Using the welding parameters to improve the mechanical properties of Liquefied Natural Gas storage tank welded joint

“…More recent work identified that heat input affects on the microstructure to improve the toughness of welded joint by controlling the cooling rates and creates types of ferrite phase and the effect of creation of ferrite types on the tensile strength of welded joint. [26][27][28]. However, this paper concern on heat input and interpass temperature as the main factors for affecting the embrittlement of weld joints, when the heat input is in suitable range and controlling the interpass temperature the in order to improve the tensile strength and toughness properties of welded joint .…”