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 ...

Although high carbon martensitic steels are well known for their industrial utility in high abrasion and extreme operating environments, due to their hardness and strength, the compressive stability of their retained austenite, and the implications for the steels' performance and potential uses, is not well understood. This article describes the first investigation at both the macro and nano sc...

Plastic pre-strains were applied to the metastable 304L austenitic stainless steel at both room temperature (20 °C) and higher temperatures (i.e., 50, 80 and 100 °C), and then the hydrogen embrittlement (HE) susceptibility of the steel was evaluated by cathodically hydrogen-charging and tensile testing. The 20 °C pre-strain greatly strengthened the steel, but simultaneously significantly increa...

Motivated by experimental observations of H. Seiner et al., we study the nucleation of austenite in a single crystal of a CuAlNi shape-memory alloy stabilized as a single variant of martensite. In the experiments the nucleation process was induced by localized heating and it was observed that, regardless of where the localized heating was applied, the nucleation points were always located at on...

NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19' martensite transformation are induced by plastic deformatio...

This manuscript aims to present an overview of quenching and partitioning (Q&P) heat treatment usually applied transformation-induced plasticity (TRIP) duplex steels (DP). TRIP DP are the first generations advanced high-strength (AHSS). AHSSs multiphase microstructures that ensure advantageous combination strength ductility. The Q&P process obtain a mixed microstructure with martensite ...

Article history: Received 29.05.2012. Received in revised form 27.07.2012 Accepted 03.09.2012. The influence of sub-temperature quenching temperature on the tensile strength, hardness and toughness of 60Si2Mn steel has been studied, and the ferrite content, austenite grain size and martensite morphology of the microstructure of this steel after sub-temperature quenching analyzed. The results sh...

Abstract--In this investigation, the fracture surfaces of SS 304 and SS 316 austenitic steels were analysed using the X-ray fractography technique. In both cases, a decrease in the austenite content was observed at the fracture surface as a result of deformation induced martensite, indicating a linear relation with Km~ within the stable crack growth region. The presence of this martensite was f...

In the present work, hydrogen/material interaction with two austenitic steel types, created via a completely different alloying strategy, is investigated. The steels include 304L stainless (ASS) and 18Mn-0.6C twinning-induced plasticity (TWIP) steel. Constant extension rate tensile tests are performed to evaluate influence of hydrogen on deformation fracture mechanisms. A reference condition wi...