The Thermal Stability of Quenched and Partitioned Steel Microstructures

The quenching and partitioning (Q&P) process is a heat treatment process, aiming at the creation of steel microstructures composed of martensite and retained austenite. Herein, the thermal stability of the microstructure is investigated upon reheating steel microstructures, created with different Q&P settings, in different thermal...

Austenite Formation from Martensite in a 13Cr6Ni2Mo Supermartensitic Stainless Steel

The influence of austenitization treatment of a 13Cr6Ni2Mo supermartensitic stainless steel (X2CrNiMoV13-5-2) on austenite formation during reheating and on the fraction of austenite retained after tempering treatment is measured and analyzed. The results show the formation of austenite in two stages. This is probably due to inhomogeneous...

Investigation of Deformation Mechanisms in Deep-Drawn and Tensile-Strained Austenitic Mn-Based Twinning Induced Plasticity (TWIP) Steel

The effect of strain on the deformation mechanisms in an austenitic Mn-based twinning induced plasticity (TWIP) steel is investigated using magnetic measurements, XRD, positron beam Doppler spectroscopy, and finite element method simulations. The experimental observations reveal the formation of a0-martensite at specific degrees of deformation,...

?' Martensite formation in deep-drawn Mn-based TWIP steel

To understand the formation of ?'-martensite in high stacking fault energy twinning-induced plasticity steel deformed in the deep drawing mode, the existing phases were investigated using magnetic and transmission electron microscopy (TEM). Small fractions of ?'-martensite were quantitatively determined by magnetization saturation experiments...

Overview of mechanisms involved during the quenching and partitioning process in steels

The application of the quenching and partitioning (Q&P) process in steels involves a microstructural evolution that is more complex than just the formation of martensite followed by carbon partitioning from martensite to austenite. Examples of this complexity are the formation of epitaxial ferrite during the first quenching step and the...

Microstructural development during the quenching and partitioning process in a newly designed low-carbon steel

This paper presents a detailed characterization of the microstructural development of a new quenching and partitioning (Q&P) steel. Q&P treatments, starting from full austenitization, were applied to the developed steel, leading to microstructures containing volume fractions of retained austenite of up to 0.15. The austenite was...

Influence of interface mobility on the evolution of austenite-martensite grain assemblies during annealing

The quenching and partitioning (Q&P) process is a new heat treatment for the creation of advanced high-strength steels. This treatment consists of an initial partial or full austenitization, followed by a quench to form a controlled amount of martensite and an annealing step to partition carbon atoms from the martensite to the austenite. In...

Microstructural Evolution of a Low-Carbon Steel during Application of Quenching and Partitioning Heat Treatments after Partial Austenitization

The “quenching and partitioning” (Q&P) process has been studied in a low-carbon steel containing 1.1 wt pct aluminum by heat treatments consisting of partial austenitization at 900 °C and subsequent rapid cooling to a quenching temperature in the range between 125 °C and 175 °C, followed by an isothermal treatment (partitioning step) at 250 °C...

The Cementite Spheroidization Process in High-Carbon Steels with Different Chromium Contents

The cementite spheroidization process is investigated in hypereutectoid steels with different chromium (Cr) contents. A spheroidized structure in high-carbon steel is usually obtained by a divorced eutectoid transformation (DET) reaction, which occurs during slow cooling of austenite with fine cementite particles. A bimodal distribution of...