Carbon Steel Type Research Articles

The solid particle erosion of 12 metals using magnetite erodent

To aid in the materials selection for sales gas control valves, the solid particle erosion behavior of 12 metals was investigated using impinging jets of magnetite particles. The erosion rates were measured for two different particle sizes, two different velocities, and six different impingement angles. In most cases, the dependencies of erosion rate on impingement angle were fit to a published semi-empirical erosion model so that they can be used in future computational fluid dynamics models of the erosion of control valves and other pipeline components. The most erosion resistant materials were found to be tungsten carbide (WC) and Stellite 12, and the least erosion resistant materials were nickel plated A1018 carbon steel and A240 type 410 stainless steel plates. There was no measurable erosion for the WC samples, even for very long exposure times. Scanning electron microscopy was used to investigate the erosion mechanisms. For the nickel plated steel, under some of the studied conditions, the plating was found to delaminate, resulting in a brittle erosive response. For all other tested materials, the measured erosion rates and scanning electron micrographs indicated a ductile erosion mechanism under all the considered conditions. With all other conditions being equal, the erosion rate was found to increase with decreasing particle size. This counter intuitive result was demonstrated to be primarily due to the formation of a thicker hardened layer which also led to a higher degree of particle fragmentation, when utilizing the larger particles as the erodent.

Influence of the butt joint design of TIG welding on corrosion resistance of low carbon steel

The aim of this work is to study the influence of the joint design of Tungsten Inert Gas welding (TIG) on the corrosion resistance of low carbon steel (type St-37). A single V-butt joints of a low carbon steel plates are performed by the Vangles 30°,45°,60° and square butt joint (angle 90°). Corrosion behavior of welded specimens in 3.5% NaCl solution was examined using Tafel polarization measurements. The corrosion behavior of the welded joint also is determined by open circuit potential (OCP) after that the cell’s current is changed due to increasing in potential by ±100. The results shown that the corrosion rate of welded joint with V-angle of 30° was found to be less than that of other angles (45°,60° and 90°). It found that the corrosion resistance of base metal was better than that of all welded joints. From the results of the microstructure it is evident that the joint design or geometric shape of weld has an important role in the welding process, when the preparation angle value of the weld gets bigger, the faults gets less due to increase of heat quantity in the weld region.

The Significance of Correlation Dimension Obtained from Electrochemical Noise

The corrosion types of Q235 carbon steel and nuclear grade 304 stainless steel (304 NG SS) in different solutions are investigated by electrochemical noise (EN) technique. EN data are analyzed by using phase space reconstruction theory. With the obtained correlation dimension from the phase space reconstruction, the chaotic behavior of EN is quantitatively evaluated. It is concluded that local corrosion shows a higher correlation dimension while passivation shows a lower correlation dimension. We propose that the correlation dimension increases with the complexity and uncertainty of the signals from passivation to local corrosion, which is the physical meaning of correlation dimension for EN.

Effect of Titanium Addition on Behavior of Medium Carbon Steel

This work aims at investigating the influence of titanium addition on behavior of medium carbon steel. Three types of medium carbon steel with different titanium content and one reference steel titanium free were produced in 100 kg induction furnace. Titanium addition was increased up to 0.230%. The produced steels were forged at start temperature 1150°C. Forging process was finished at temperatures 900°C, 975°C, and 1050°C. Microstructure examination and hardness measurement were carried out for forged steels. Mechanical properties and impact measurements were carried out for quenched tempered steels. Ti addition was found to have significant influence on refinement of grains and increase of ferrite/pearlite ratio. It was also, observed that grain size decreases as finishing temperature of forging process decreases. Both Ti addition and lowering finishing forging temperature have positive effect on hardness. In addition, results indicated that addition of titanium has significant effect on the mechanical properties and toughness.

English

    An AISI 304 type of austenitic stainless steel and low carbon steel were cladded by explosive welding in this study. Four explosive loading rates were used with the range of 1 and 2.0. Stand-of distance (s=t) was also used as a welding parameter. Cladded materials have been subjected to heat treatment at 250°C for times of ranging from 1 to 4 h. Effect of heat treatment on the microstructure and mechanical properties has been evaluated using optical and scanning electron microscopy, EDS analysis technique and hardness tests, respectively. The results indicate that straight and wavy structures of bonding at the interface were obtained according to the loading of explosive rate. The grain size of the cladded materials near the interface were increased with the duration of heat treatment. Hardness values at the interface of the cladded materials were decreased with the increment of heat treatment period.   Key word: Explosive welding, hardness, microstructure, stainless steel, low carbon steel. &nbsp

Theoretical study on Manson-Coffin equation for physically short cracks and lifetime prediction

The Manson-Coffin equation has been widely applied to the prediction of fatigue lifetime. But this equation does not explicitly express the relation between the fatigue lifetime and the crack length. The present paper proposes that the grain size can be replaced by the maximum non-damaging crack length. Thus, the growth rate will decrease to zero when the crack reaches this size. Combining with the theory of the fatigue short crack propagation, we derived the relations between physically short crack’s initiation-propagation rates and material’s mechanical properties, as well as crack length, stress and strain. With the derived relations, fatigue lifetime of short cracks can be successfully predicted by basic mechanical properties. Similar to the format of Manson-Coffin equation, our relations uncover the essence of Manson-Coffin equation which may reveal the short crack’s initiation-propagation mechanism. Predictions of fatigue lifetime using our relations were compared with the results of well-known experiments. Good agreement is found in many aspects, such as coefficients, exponents, as well as fatigue lifetimes, especially for short cracks around 10 micrometers. Predictions on the short crack propagation rates are also compared for 16 types of carbon steels. Satisfactory consistency shows that our relations have wide applicability.

A high fatigue life prediction methodology under constant amplitude multiaxial proportional loadings

The main aim of this study is to propose a method for prediction of the fatigue-life for different materials subjected to constant amplitude multiaxial proportional loading. The paper presents a method to solve a high-cycle-fatigue problem using linear elastic analysis via Ansys software. A computing program of the fatigue life prediction methodology was developed. This program uses both Ansys and Matlab files. It is necessary to build an interface which allows both softwares to interact. The fatigue life N can be evaluated from knowledge of both the equivalent stress and the SN curves in reversed torsion and alternating bending. The numerical simulation provides to evaluate the fatigue life N and to localize the critical region. We test the model on a carbon steel type S 45C. To demonstrate the use of algorithm developed in this work, two case study problems were solved. The first case consists of a rectangular plate, with low thickness, which is subjected to uniaxial tensile stress combined with alternating bending moment. The second case concerns a specimen, with circular cross-section, which is subjected to uniaxial tensile stress combined with alternating torsion moment. The loadings which cause infinite-life and those which generate finite-life could be distinguished. The model can also determine the safe domains in the frame with axis load forces, in order to choose the adequate force loads. For a given fatigue life, the model predicts a continuous linear relationship in which the amplitude of the alternating force decreases as the uniaxial tensile stress increases.

Finite difference simulation of low carbon steel manual ARC welding

This study discusses the evaluation and simulation of angular distortion in welding joints, and the ways of controlling and treating them, while welding plates of (low carbon steel) type (A-283-Gr-C) through using shielded metal arc welding. The value of this distortion is measured experimentally and the results are compared with the suggested finite difference method computer program. Time dependent temperature distributions are obtained using finite difference method. This distribution is used to obtain the shrinkage that causes the distortions accompanied with structural forces that act to modify these distortions. Results are compared with simple empirical models and experimental results. Different thickness of plates and welding parameters is manifested to illustrate its effect on angular distortions. Results revealed the more accurate results of finite difference method that match experimental results in comparison with empirical formulas. Welding parameters include number of passes, current, electrode type and geometry of the welding process.

Influence of Environmental Humidity on the Fretting Properties of an Applicative Metallic Material under Grease Lubrication(An Approach Based on the Slip Index)

In order to clarify the influence of environmental humidity (RH = 10-70 %) on the fretting characteristics of steels under grease lubrication an experimental investigation is performed. Ball (bearing steel) on disk (carbon steel) type fretting tests for 0-20 mg of grease supplied before each test at the punctual contact between ball and disk were conducted at 50 μm slip amplitude and 6.7 Hz frequency. From the shape of the friction hysteresis one calculates the slip index, and based on it, determines the type of fretting regime against the number of fretting cycles. Influence of the grease amount and relative humidity on the friction coefficient, wear rate and slip index is interpreted based on the occurrence of the grease film breakdown. Such results are useful to find the amount of grease necessary but sufficient for proper lubrication, and hence to protect the environment by grease saving.

Soft Soldering of Steel DIN CK50 Using ASTM 50A and ASTM 63A

The research presents some experimental data concerning the relation between the shearing strength
 of soldered joints and holding time. Two types of solders ASTM 50A (Sn50Pb50) and ASTM 63A
 (Sn63Pb37) were used to joint medium carbon steel type DIN CK50 of 3 mm thickness. Lap joint design
 was employed. Muffle furnace used for heating with holding (reflow or dwell) times of 10, 20, 30, 35, 40,
 45 and 50min. Maximum shear strength was obtained when the eutectic solder (ASTM 63A) used with 35
 min. as holding time. Clear intermetallic compounds were shown at the interface, whereas the X-ray
 detected the formation of many phases like FeSn and FeSn2.

Electrochemical Studies on Silicate and Bicarbonate Ions for Corrosion Inhibitors

Several types of carbon and high-strength low-alloy (HSLA) steels are being considered for use in the underground reinforcement of the Yucca Mountain Nuclear Waste Repository. In this study, potentiodynamic polarization under reducing conditions was used to determine the corrosion rates (CRs) and passivity behavior of AISI 4340 steel using different combinations of sodium silicate (Na2SiO3) and sodium bicarbonate (NaHCO3), in both pure water (PW) and simulated seawater (SW, 3.5 pct NaCl). These experiments were carried out to examine the potential inhibiting properties of the silicate or bicarbonate ions on the surface of the steel. The addition of sodium silicate to solution reduced the observed CR at room temperature to 19 μm/y at 0.005 M concentration and 7 μm/y at 0.025 M concentration in PW. The addition of sodium bicarbonate increased the CR from 84 μm/y (C = 0.1 M) to 455 μm/y (C = 1 M). These same behaviors were also observed at higher temperatures.

Evaluation of Electrical Resistivity of Oxide Scale Formed under Different Conditions

The nature of direct current potential drop (DCPD) on carbon steel (SS400) having different surface conditions is investigated in this study. The spring-loaded macroscopic DC four-point-probe sensor was used for the measurements of potential drop. Three samples from the same type of carbon steel are prepared under three different conditions, namely, exposures for short and long periods in atmosphere and heat treatment at low temperature of the sample experienced short exposure. In an attempt to verify the repeatability nature of DCPD, the measurements are performed on different locations of the test surface under the same experimental conditions and used for analysis. The natures of potential drop on oxide scale free surface and oxidized surfaces were compared. The effect of oxidized surfaces on DCPD in all the three cases is observed markedly. From these observations, it is worth understanding that the DCPD technique through spring-loaded macroscopic four-point-probe is able to distinguish the oxidized surface from oxide scale free surface. Finally, electrical resistivities of oxide scale in all the three cases were successfully evaluated by using electrical image method with oxidized sample considering as a two-layer structure. The almost unique value of evaluated electrical resistivity of oxide scale in all the cases indicates that the oxide materials are similar in type in respect to electrical resistivity.

Corrosion Inhibition Efficiency of Some New Surfactants on Carbon Steel Type H-11 in 1 M Hydrochloric Acid Solution

Three water soluble surfactants based on nonyl phenol were prepared, namely: ethoxylated nonyl phenol (e.o = 9), E(9)NP, ethoxylated nonyl phenol sodium phosphate, E(9)NPSP, and ethoxylated nonyl phenol phosphate diamide, E(9)NPPA. The inhibition efficiency of these surfactants on H-11 carbon steel in 1 M HCL was investigated using the weight loss technique. The surface active and thermodynamic properties of the investigated inhibitors have been studied. The surface morphology of carbon steel in absence and presence of different concentrations of E(9)NPPA was examined by environmental scanning electron microscopy (ESEM). The maximum inhibition efficiency (93.21%) was obtained by E(9)NPPA at 300 ppm and 298°K.

Evolution of void volume fraction for simulating inner fracture defects related to in drawing of high-carbon steel wire rods

Ductile fracture occurs through the nucleation, growth and coalescence of voids. In our previous study, an evolution equation, which denotes a change in void volume fraction, and a model of void coalescence were proposed and proved to be effective in the simulation of inner fracture defects in the drawing of four types of carbon steel for machine structural use. In this study, a new evolution equation, which denotes a change in void volume fraction, is proposed for the simulation of inner fracture defects in the drawing of four types of high-carbon steel wire rod. The validities of our proposed evolution equation and model of void coalescence are clarified by comparing analytical results with experimental results.

Erosion-Corrosion of Carbon Steels in a Laboratory: Three-Phase Flow

Abstract A new testing facility for a high-velocity, three-phase flow consisting of a gas flow loop and a jet impingement rig is described. Flow velocities between the nozzle and specimen have been determined through computational fluid dynamics (CFD) simulations and by particle image velocimetry. Tests were conducted on typical carbon steels (J55 and C95) that are used in tubings for the gas and oil industry. Flow conditions of a sweet gas condensate well have been applied. Mass-loss rates have been determined after testing times of between 4 h and 168 h using optical profilometry. Damaged surfaces were investigated using optical and scanning electron microscopy. The effects of material and flow velocity on the mass-loss rate have been investigated. Mass loss of specimens under given conditions is determined by siderite formation and increasing degradation of siderite layer by impacts of sand and fluid droplets. Degradation happens by erosion-enhanced corrosion. Normalized steel J55 behaves like a ductil...

Laser Direct-Part Marking of Data Matrix Symbols on Carbon Steel Substrates

Certain applications have recently appeared in industry where a traditional bar code printed on a label will not survive because the item to be tracked has to be exposed to harsh environments. Laser direct-part marking is a manufacturing process used to create permanent marks on a substrate that could help to alleviate this problem. In this research, a 532 nm Nd:YAG laser was utilized to produce Data Matrix symbols onto carbon steel substrates. The quality of the laser marked Data Matrix symbol was then evaluated according to the ISO/IEC 16022 bar code technology specification for Data Matrix. Several experiments were conducted to explore the effects that different parameters have on the quality of the laser direct-part marked symbols. Parameters such as type of carbon steel, percent of laser tool path overlap, profile speed, average power, and frequency were found to have significant effects on the quality of the Data Matrix symbols produced with the laser. The analysis of the results indicated that contrast and print growth were the critical ISO/IEC 16022 standard performance measures that limited the laser marked Data Matrix symbols from achieving a higher final grade.

Galvanic Coupling Between Carbon Steel and Stainless Steel Reinforcements

Galvanic corrosion is a potentially major concern associated with the application of stainless steel reinforcement which is in direct (electrical) contact with carbon steel reinforcement in concrete structures. Judicious use of stainless steel rebar in both new construction and rehabilitation of older structures is a viable, cost effective option for extending service life and reducing maintenance costs. Questions, however, have arisen about the possibility of increased corrosion due to galvanic effects. This paper investigates the galvanic coupling behaviours of three different types of stainless steel and carbon steel. Tests were performed both in electrochemical cells and with specimens in concrete inside an environmental chamber. The results show that oxygen reduction on stainless steel is the rate determining factor for galvanic coupling of these two metals. It is much lower than that of passive carbon steel. As a result, the galvanic coupling of stainless steel with carbon steel will not increase the risk of corrosion of carbon steel reinforcement.

Different Types of Carbon Steel Enhanced Tubes in Ammonia Flooded Evaporator

This short paper deals with a real-world case study of a large capacity industrial ammonia-flooded evaporator. Ethylene glycol brine was the process fluid to be cooled. Several options were analyzed (e.g., different versions of shell-and-tube and plate-and-frame heat exchangers). Because of mechanical integrity, control issues, and maintenance requirements, the option of choice was a flooded shell-and-tube. A conventional flooded shell-and-tube with plain surface carbon steel tubes would have been too big, resulting in a large space requirement and greater refrigerant charge. Almost every local code requires the careful audit of ammonia inventory in an industrial plant. The goal of the designers, engineers, contractors, and the end users is to reduce the refrigerant charge to a minimum. In view of design and operational constraints, an evaporator was designed, fabricated, and installed that included a tube bundle with various kinds of tubes. Three different types of tubes were used along the height of the tube bundle. Highly efficient, nucleate boiling characteristics doubly-enhanced tubes were used in the lower section, and inside-only enhanced tubes were used in the top section to minimize the adverse effects of vapor blanketing. Tubes in the midsection were doubly-enhanced with a different outside structure than the tubes in the lower section. This resulted in a very efficient evaporator at a minimum refrigerant charge.

Effects of mechanical properties on the tribo-electrification mechanisms of iron rubbing with carbon steels

The mechanisms of tribo-electrification and the associated wear behavior of a pair of dissimilar metals in the form of a pin and a plate rubbing against each other under dry severe wear condition were investigated using a reciprocating friction tester. The materials were iron and carbon steels of 0.2%, 0.45% and 0.7% carbon. Results showed that when an iron pin rubbed against the steel plate specimens, increasing the carbon content caused the formation mechanism of the wear particle to vary from macro-asperity removal to yielding wear. The material adhesive transfer was mainly from the pin to the plate specimen due to yielding wear. Hence, the polarity of tribo-electrification for the pin specimen varied from random to positive. Consequently, a model that described this mechanism was proposed. Now, when the materials were reversed, i.e. the three types of carbon steels were used as the pin to rub against an iron plate, increasing the carbon percentage of the pin specimen resulted in the wear mechanism to vary from macro-asperity removal to grooving wear, the latter of which resulted in material transfer mainly from the plate specimen to the pin specimen. In contrast to the previous case, the polarity of tribo-electrification for the pin specimen varied from random to negative and a model that described this mechanism was proposed. Based on the above two models, a micro-model of tribo-electrification mechanism for self-mated materials was proposed. By using this micro-model, the mechanism of tribo-electrification in same material abrasion can be reasonably explained.

GALVANIC COUPLING BETWEEN CARBON STEEL AND STAINLESS STEEL REINFORCEMENTS

Galvanic corrosion is a potentially major concern associated with the application of stainless steel reinforcement which is in direct (electrical) contact with carbon steel reinforcement in concrete structures. Judicious use of stainless steel rebar in both new construction and rehabilitation of older structures is a viable, cost effective option for extending service life and reducing maintenance costs. Questions, however, have arisen about the possibility of increased corrosion due to galvanic effects. This paper investigates the galvanic coupling behaviours of three different types of stainless steel and carbon steel. Tests were performed both in electrochemical cells and with specimens in concrete inside an environmental chamber. The results show that oxygen reduction on stainless steel is the rate determining factor for galvanic coupling of these two metals. It is much lower than that of passive carbon steel. As a result, the galvanic coupling of stainless steel with carbon steel will not increase the risk of corrosion of carbon steel reinforcement.