Martensite

this paper, the hardness and c/a ratio of tempered martensite for AISI 4140 were measured by X-Ray Diffraction and Rietveld refinement. The result reveals that the c/a ratio decreases instantly within the first 60s tempering time. After analysis based on the experiment results and derivation of Hollomon-Jaffe equation, c, the parameter in Hollomon-Jaffe equation, is found to stand for the slope of carbon-hardness curve. Key words: Tempering, martensite, X-ray diffraction, Hollomon-Jaffe equation 1

Table of Contents 1. INTRODUCTION 1 1.1. Definition 1 1.2. Displacive Transformations 1 1.3. Hysteresis 2 1.4. Crystal structures of Ti-Ni based martensites 3 1.5. Spectroscopy techniques to determine composition of SMA 4 1.5.1. Energy Dispersive X-Ray Spectroscopy 4 1.6. Phase diagram of Ti-Ni Alloys 5 2. APPLICATION OF SHAPE MEMORY ALLOYS IN INTELLIGENT REINFORCED CONCRETE STRUCTURES (IRCS) 7 2.1. Concept of IRCs 7 2.2. Important Shape Memory Alloy Properties Applied in IRC 7 2.2.1. Shape Memory

in practice make IRCs viable for only extremely specialised applications. Due to the thermomechanical propertied of SMAs, the IRC properties may vary with the ambient temperature (Menna et al, 2014; pg33). In addition, as the mechanism of the martensite to austenite phase transformation requires heating, the actualisation of the large-scale heating of the IRC poses an extra hurdle to their application. Min et al (2011) also note that certain hydration products of cement are unstable at and following

INTRODUCTION The Shape Memory Alloys are quite fascinating materials characterised by a Shape Memory effect and Super-elasticity, which ordinary metals and alloys do not have. This unique behaviour was first found in Au-47.5%Cd alloy in 1951, and was publicised by its discovery in a Ti-Ni alloy in 1963. After much research and development thereafter, shape memory alloys are now being practically used as new functional alloys for pipe couplings, antennae for cellular phones and various actuators

unit microstructure of the DP steels. DP steels despite their name consist of three or more phases including ferrite, martensite, banite, retained austenite and pearlite. The Matrix in DP steels is soft ferrite and the strengthening phase is martensite. In some cases banite and retained austenite also contribute to strengthening. Ferrite enables low initial yielding stress and martensite enables the high ultimate tensile strength (UTS). The above characteristics make the DP steels ideal alloy systems

1. Chemical composition of DP600 steel Steel grade C Max Si max Mn max P max S Max Al Nb Max Cr+Ni+Cu Max DP 600 0.14 0.50 1.40 0.085 0.008 0.02-0.06 0.009 1.30 Dual phase steel has a microstructure which consists of two phases, Ferrite and Martensite (Fig.1). DP600 steels have a tensile strength of around 600 MPa and total elongation of about 20-25% (Fig2). The tensile strength of DP600 steel can vary from 580-670 MPa.Write uses ???????. Other advantages of DP600 steels are

“Production process for ferrite-martensite DP600 steel with 30-35% total elongation” Team Members- Kishan - B.Tech (Juniour Undergraduate), Dept. of Metallurgical Engineering, IIT (BHU) – 13145020 Lal Babu Singh - B.Tech (Juniour Undergraduate), Dept. of Metallurgical Engineering, IIT (BHU) – 13145024 Contents: 1. The Concept of Dual Phase steels. 2. Factors influencing mechanical properties of Dual Phase steels. 3. The Challenge: Increasing total elongation without compromising

Influence of alloying elements on pearlite formation 14 Martensitic Transformation 14 Influence of alloying elements on martensite formation: 16 The basis of calculating TTT diagram for ferrous system 16 Bainite start temperature Bs from Steven and Haynes formula 16 Ms Temperature 17 Transformation Start and Finish C curves 18 Fractional transformation time 18 Fraction of martensite as a function of temperature 19 Bibliography 19 Introduction to Time – Temperature – Transformation (TTT) diagram

Material Properties of Steel Steel is an alloy of iron, with carbon being the primary solute in the solid solution. It is a polycrystalline solid with grain diameter from 10 to 20 micro-meter (Ashby et al). The presence of impurity like carbon causes the crystal lattice distortions to increase, hence making giving steel better hardness, yield strength, and tensile strength, at the cost of ductility. Pure iron being very ductile but comparatively weak, steel is widely because of its greater load bearing

Introduction Metallurgy is the field of materials science and material engineering that studies the physical and chemical behaviour of metallic elements, their microstructure compounds and their mixtures, which are mostly known as alloy. Metallurgy can be refers as the technology of metals where science is applied to the production of metals, and the engineering of metal components for the uses of products for consumers and manufacturers. Metals are widely use in industrial, economic growth and