aisi 4340 steel is one of the super strong steels that can be selected for different applications. by designing theproper cycles of heat treatment, the optimum microstructure and properties of this steel can be achieved. in thisstudy, different heat treatment cycles were introduced to achieve the optimum microstructure and improve themechanical and magnetic properties of aisi 4340 steel. the re...

Martensitic and bainitic steels are two types of widely used steels with excellent mechanical behaviors in automatic industry. It’s universally acknowledged that asquenched martensite possesses poor ductility and impact toughness, which should be tempered before putting into application. During tempering, as-quenched martensite changes from a hard and brittle microstructure to more ductile and ...

There is general agreement that a weld microstructure primarily containing acicular ferrite will exhibit high strength and excellent toughness due to its small grain size, high dislocation density, and the way in which the plates are dispersed in the microstructure (Pargeter, 1983; Sneider and Ken, 1984). In contrast, the presence of allotriomorphic ferrite, ferrite plates with aligned carbides...

Abstract This paper examined the cyclic deformation behaviour of multiphase low-carbon steel that was subjected to austempering heat treatments at four temperatures (190 °C, 230 275 and 315 °C) below martensite start temperature ( M s = 353 °C). The tests were conducted room temperature, under fully reversed strain-controlled conditions, with strain amplitudes in range 0.5–1.0%. microstructure ...

The neutron irradiation response of a novel hot isostatically pressed SA508 Grade3 steel was studied, such to deduce any influence this unconventional RPV microstructure has on radiation response. In particular, the role elevated ferrite fraction investigated. Neutron conducted at 155 ± 10°C induce 0.1dpa damage, corresponded 2.53 0.63 GPa hardening for and 1.94 0.57 bainite as measured by nano...

There has long existed a controversy regarding the formation of the bainite phase in steels. Nonetheless, following the clear identification of bainite in 1930, several characteristic features associated with the bainite transformation became well established. These features include: the classification into upper and lower bainite; the existence of a bainite-start temperature; and the incomplet...

Microstructure and properties have been studied for high strength steel weld metals with variations in carbon, manganese and nickel. Based on neural network modelling, experimental welds were made using shielded metal arc welding with manganese at 0.5 or 2.0 wt. % and nickel at 7 or 9 wt. %. Additional welds were made where carbon was varied between 0.03 and 0.11 wt. %. Generally there was very...

Armour steel is a medium-carbon which widely used in military and defense industries owing to its ability protect from projectile bullet pressure. However, this armour still posses mechanical limitation aspect, thus it needed engineer for improvement. Therefore, the aim of research undergo properties engineering by using heat treatment method austempering within temperature variations 200, 250,...

the development of nano/ultrafine bainitic structure in aisi 52100 steel was the goal of this study. for this purpose,the aisi 52100 the specimens were austenitized at 1050 °c for 60 min followed by low-temperature austemperingtreatment at different temperatures and times. the austempered samples were characterized using field emissionscanning electron microscopy (fesem), x-ray diffraction (xrd...

In the current research, a complex microstructure and crystallographic data were developed through quenching partitioning (Q&P) process to improve tensile properties of commercial pearlitic carbon-silicon steel. Two-stage Q&P process, including full austenitization, at 220 °C, followed by two different temperatures, was applied as-received specimen generate composed tempered martensite, bainite...