Calculations verify that carbon diffusion may occur during the lath martensite fomtion. Accordingly,the diffusion of int2rstitial ator ions must be taka into account nhfn martmitic transformtion is defined as a diffusionless transformation. In derivation of the kinetics equation of the ath& martensitic transfomtion,rzgardng the c a r h diffusion, i .e.the enrichment of the austenite during the ...

alloy steel, which is versatile in such qualities as grade, property and application, can play an important role in the technical and economic development of the country. the present consumption of the key industrial sector to this strategic material, specified basically as semi- finished products exceeds 100,000 tons per year. however, a rough estimation of the true potential needs, does clear...

This paper was aimed to address the modeling and optimization of factors affecting the corrosive wear of low alloy and high carbon chromium steel balls. Response surface methodology, central composite design (CCD) was employed to assess the main and interactive effects of the parameters and also to model and minimize the corrosive wear of the steels. The second-order polynomial regression model...

Due to the recent droughts, the retube of Sezela evaporators was delayed for a few years, resulting in a need for a low cost carbon steel tube to retube five evaporators. A recent failure highlighted the importance of the heat treatment and expansion characteristics of these tubes. This paper discusses the failure of a carbon steel tube, the development of the heat treatment of locally manufact...

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...

The carbon based coils with the nanometer scale have the 3 dimension helix geometry. We synthesized the carbon nano-coils by the use of chemical vapor deposition technique with iron and tin as the catalysts. The fabricated coils have the external diameter of ranging few hundred nm to few thousand nm. The Scanning Electro-Microscope (SEM) and Tunneling Electro-Microscope has shown detail images ...

Investigations were carried out to study the effects of heat treatment on the mechanical properties of rolled medium carbon steel. The steel was heated to the austenizing temperature of 830C and water quenched; It was reheated to the ferrite – austenite two phase region at a temperature of 745C below the effective Ac3 point. The steel was then rapidly quenched in water and tempered at 480C to p...

In this study we propose a unified multi-scale chemo-mechanical description of the BCT (Body-Centered Tetragonal) to BCC (Body-Centered Cubic) order-disorder transition in martensitic steel by adding the mechanical degrees of freedom to the standard CALPHAD (CALculation of PHAse Diagrams) type Gibbs energy description. The model takes into account external strain, the effect of carbon compositi...

The effects of steel wire patenting process parameters on very fine interlamellar spacing in the pearlitic steel wire were investigated and the optimized condition of the process was achieved. In this work, the initial nanopearlitic structure was obtained in a 0.72 wt% carbon steel wire before the wire drawing process. The results were the minimum interlamellar spacing of 35 nm and maximum ulti...