Carbon steel

About: Carbon steel is a research topic. Over the lifetime, 22395 publications have been published within this topic receiving 233330 citations. The topic is also known as: high-carbon steel.

Laser welding of dissimilar carbon steel to stainless steel 316L

Abstract: Laser welding of metals and alloys is extensively used in industry due to its advantages of controlled heating, narrow weld bead, low heat affected zone (HAZ) and its ability to weld a wide range of metals and dissimilar metals. Laser welding of dissimilar metals such as carbon steels and stainless steel is still a challenging task, particularly due to the formation of brittle phases in the weld, martensitic formation in the HAZ and solidification cracking in the fusion zone. These issues can significantly deteriorate the strength of the welded joint. The aim of this work is to investigate the fundamental phenomena that occur inside the dissimilar weld zone and their effect on weld quality. In order to establish the key process variables, an initial study concentrated on the effect of different laser process parameters on dissimilar weld quality. In the second part of the work, a comprehensive study was performed to understand and subsequently control the alloying composition in laser dissimilar welding of austenitic stainless steel and low carbon steel. A dissimilar weld that is predominantly austenitic and homogeneous was obtained by controlling the melt pool dynamics through specific point energy and beam alignment. The significance of dilution and alloying elements on joint strength was established. A coupled CFD and FEM numerical model was developed to assist in understanding the melt pool dynamics and transportation processes of alloying elements. The model has been validated by a series of laser welding experiments using various levels of specific point energy. The laser welding characteristics in terms of geometric dimensions, surface morphology, alloying concentration, and dilution, were compared, and it is concluded that the specific point energy and laser beam position are the key parameters that can be controlled to obtain a weld bead with characteristics most suitable for industrial applications. In the third part of the work, a comparative study was performed to understand the significance of cooling rate, and alloying composition on the microstructure and phase structure of the dissimilar weld zone. Results show that the HAZ within the high carbon steel has significantly higher hardness than the weld area, which severely undermines the weld quality. A new heat treatment strategy was proposed based on the results of the numerical simulation, and it is shown to control the brittle phase formation in HAZ of high carbon steel. A series of experiments was performed to verify the developed thermo-metallurgical FEA model and a good qualitative agreement of the predicted martensitic phase distribution is shown to exist. Although this work is presented in the context of dissimilar laser welding of mild steel to stainless steel, the concept is applicable to any dissimilar fusion welding process.

Checking Surface Contamination and Determination of Electrical Resistivity of Oxide Scale Deposited on Low Carbon Steel by DC Potential Drop Method

Abstract: This article describes about the nature of potential drops (PDs) on carbon steel (SS400) and stainless steel (SUS304). The experimental results showed the remarkable nature of potential drops on oxidized surface. Direct current PD (DCPD) technique was used to investigate the nature of potential drops on the test surfaces with probe contact time. The nature of PDs on oxidized and oxide scale free surfaces were compared for the same experimental conditions and it is easy to compare the contaminated surface with oxide scale free surface and to decide whether the surface is oxidized or clean. Oxidized test surface is considered as two layers of different resistivities. The effect of two layers on the potential drops was illuminated by electrical image method. Electrical resistivity of oxide scale was determined by DCPD technique on the basis of the two layers of different resistivities model. In an attempt to verify the accuracy and prove the validity of the proposed method, the electrical resistivity is also determined at different probe spacing and all the results are shown to be very proximate to one another.

Two-phase high tensile hot rolled steel plate comprising two-phase structure of ultra-fine grain ferrite phase and hardening phase and preparation tehereof

Abstract: PURPOSE: To inexpensively prepare a two-phase high tensile hot rolled steel plate comprising two-phase structures of an ultra-fine grain ferrite phase and a hardening phase, by rolling carbon steel having a specific composition containing C, Si and Mn at a specific rolling temp. under a specific draft while quenching the rolled steel. CONSTITUTION: Carbon steel containing 0.02W0.2% C, 1.0% or less Si and 1.5% or less Mn and substantially containing no special components is rolled in a temp. range of Ar 3 +100°CWAr 1 +50°C within 2sec under such a condition that a sum draft is 60% or more and a total draft of one-pass or more is 50% or more to form a structure consisting of 50W95% or an ultra-fine ferrite phase and the remainder of an austenite phase while the rolled steel is quenched at a cooling speed exceeding 20°C/sec to obtain a two-phase high tensile hot rolled steel plate comprising the ferrite phase with an average grain size of 5μm or less and a hardening phase. In the above mentioned method, the rolling temp. and the draft are regulated to make it possible to adjust the amount and grain size of the ferrite phase. COPYRIGHT: (C)1984,JPO&Japio

Effects of Seasonal Conditions and the Slope of a Specimen on the Atmospheric Corrosion of Steel in the Tropics of Viet-Nam

Abstract: The results of the field tests of a plain carbon steel in the rural and marine atmospheres of the Northern Vietnam are discussed. The steel specimens were exposed in various year seasons at slope angles of 30° and 45° to the horizontal. The meteorological and aerochemical parameters of enviroment were simultaneously recorded. The effect of the slope angle was noticeable at early stages of the corrosion of a specimen. On the completion of a year-long climatic cycle, the difference in the corrosion effects on the specimens with both the above slope angles did not exceed 10%. During the winter season, the corrosion of the steel is determined by an increased integral time of wetness, TOW (that is, the life time of the films of a corrosive electrolyte at the metal surface).

A study on oxide scale formation of low carbon steel using thermo gravimetric technique

Abstract: The aim of this paper was to investigate the effect of oxygen content and temperature on the formation of oxide scales of four different steel grades. Thermo gravimetric experiments were carried out. Small samples of low carbon steels with different compositions were exposed to a gas containing a certain amount of oxygen and at temperatures in the range of 1373-1623 K. The mass gain of the steel sample was recorded. On the basis of the oxidation curves, the parabolic rate constants were reported. Post-experimental investigation of the samples was performed using scanning electron microscope and light optical microscope techniques. The results were compared with the scanning electron microscopy graphs of the steel samples taken from the real industrial reheating furnace.