Steel Wire Rod Research Articles

Strain aging in C-Mn-Si steel wire rod with multi-phase microstructure

Strain aging in C-Mn-Si steel wire rod with multi-phase microstructure

Induction Heating Technology for Steel Wire Processing

This article discusses the induction heating application features in metallurgical industry for previously unused objects, such as wire coils and wire rod bundles. The analysis of international trends and a forecast of the induction heating application shows a steady expansion of the induction technologies in the metallurgical industry. The article considers the advantages of induction heating in comparison to other competitive technologies. Heat treatment in electrotechnological induction plants is determined by the interconnected electric and thermophysical processes taking place in them, the complex nature of the internal heat sources distribution, the dependence of the distribution pattern of the induction plant on the temperature of the products being processed. It is shown that the investigation results of the induction heating method influence the temperature and time factors in the formation of the structure, the increase in the uniformity of heating, and the quality of the heat treatment of steel wire and wire rod buntle, taking into account the stated technological task. The efficiency estimation of application of medium and high-frequency induction heating of steel wire of various diameters is given. Evaluation of the efficiency improving of the induction heating device, when the heat treatment simultaneous multiple strands of steel wire of equal diameter, united in a bundle, is given.

Investigation of Notch Shear Cutting for JIS SCM420 Steel Wire Rod

This paper aims to study the notch shear cutting of JIS SCM420 steel wire rod. In the notch shear cutting experiment, the wire rod specimens were initially notched on the surfaces using a sharp insert installed at a lathe turning machine. Then, the specimens were cut off using the punch/die shearing tool. After the shear cutting, the sheared edge features of the wire rod were investigated and compared with the results obtained from the conventional shear cutting. In addition, the geometry of the notch, the notch depth, was varied ranging from approximately 333 to 537 μm and studied. The experimental results revealed that the cutting load resistance significantly decreased with the notch shear cutting technique. The roll over and the size of the burr zones also decreased, compared to the conventional shear cutting. This technique also improved the quality of the sheared edge in term of the roundness of the wire rod. Concerning the notch depth, it was a primary factor affecting the cutting results, especially the cutting load resistance and the occurrence of the long burr protruded from the surface of the wire rod. The improvement of the sheared edge quality by the notch shear cutting seemed to be caused by the suppression of the plastic deformation of the wire rod during shearing.

Methodology of High-Carbon Wire Rod Perlite Grain Grade Identification

The quality of the high-carbon rod is determined by mechanical properties, which depend on microstructure characteristics, in particular the perlite grain grade. The existing technique for determining the perlite dispersion has the main drawback - the subjectivity of choosing the five worst view fields for evaluation, which reduces the accuracy of the determination results. The article presents the results of a study aimed at increasing the objectivity and accuracy of the evaluation of high-carbon wire rod perlite grain grade. An improved technique for determining the high-carbon wire rod perlite grain grade – Pgg with five view fields is proposed. The cross-section of the rod sample is considered as an inhomogeneous area from the perlite dispersion point of view, which is divided into three annular zones with different levels of perlite dispersion. Selection of five view fields is carried out as follows: one from the center of the central zone, two fields in the second - an intermediate zone and two fields in the outer zone. Statistical analysis of the experimental data showed that all view fields should be located on the same diagonal. The location of the view fields is fixed and is unchangeable for all samples under study. The technique described in the article is an effective tool for analyzing the structure of high-carbon steel wire rod.

Effect of Controlled Cooling after Hot Rolling on the Mechanical Properties of a Low Carbon Niobium Microalloyed Steel Wire Rod

The wire rod has high relevance due to its wide application as a raw material for steel wire and wire processed in cold rolling mills and drawing. The control of process variables, such as cooling rate, coiling temperature, rolling speed is essential for obtaining the microstructures and therefore mechanical properties of the material. The purpose of this work is to study the behavior of the microstructure and mechanical properties with the variation of thermomechanical treatment in the hot rolling of wire rod. The steels used in this study were the microalloyed niobium steel equivalent to ASTM A913 grade 50 and carbon steel equivalent to ASTM A510 grade 1013. Despite the carbon steel has higher equivalent carbon to microalloyed steel, was found higher yield strength (σe) in the microalloyed niobium steel. Thus, by applying appropriate thermomechanical treatment in microalloyed steel is possible to improve mechanical properties mainly due to grain refining.

The temperature distribution and underlying cooling mechanism of steel wire rod in the Stelmor type cooling process

The temperature distribution within wire ring during the Stelmor type cooling process has been investigated to understand the underlying cooling mechanism of steel wire rod using the well-designed off-line simulator and numerical simulation. The temperature deviation within wire ring varied with increasing air velocity and the maximum temperature deviation occurred at the air velocity of 10 m/s. Interestingly, the middle and inner edge regions of wire ring had a higher cooling rate than the center region under the air blowing cooling conditions because the air velocity around middle and inner edge regions was higher than that around center region. The cooling behavior of edge region is highly related to the ring pitch: the cooling rate of edge region dramatically decreased with decreasing ring pitch due to the more complicated ring structure. The proposed empirical equations as a function of wire diameter and air velocity can predict the cooling rates of wire ring well at both center and edge regions, which is a great benefit in industrial applications.

Strain Aging in Boron Alloyed Multi-Phase С- Mn – Si – Steel Wire Rod

The specimens of C – Mn – Si - steel wire rod 5.5 mm in diameter with 0.005% B and without B additions from Moldova Steel Works had been studied. It was been established by crystallographic-geometrical analysis, that the boron atoms could be allocate in B – alloyed a – Fe only in the positions of a sub-interstitial solid solution. By study a static strain aging (SSA) and a dynamic strain aging (DSA) specimens of wire rod by C – Mn – Si - steel with B and without B (both with multi-phase (ferrite- martensite (bainite)-pearlite) microstructures) more expressed decreasing of strengthening properties and higher characteristics of ductility had been determined for C – Mn – Si - steel specimens with B. These results could be explained by “de - nitrogenous” and “de - carbonaceous” mechanisms, when boron atoms from a – Fe sub-interstitial solid solution by producing wire rod and by its strain aging thermal treatment with temperatures 150 - 450 °С generate boron- nitrogenous and boron - carbonaceous – nitrogenous precipitations. By realizing these mechanisms nitrogen and carbon atoms are partly excluded from the dislocation pinning’s process. This, in fact, explains to inhibit the development of strain aging (SSA and DSA) in boron- micro-alloyed C – Mn – Si - steel.

Quality Control of the Steel Wire Rod Product by Integration Lean Six Sigma and Taguchi Method

RMW Inc. is the global company in Indonesia. One of its product is the steel wire rod. This research aims to control the production process and improve the product quality. This research is using the integration between lean six sigma and taguchi method. The first step is to reduce the waste using lean six sigma method while the second step is to reduce the defect using taguchi method. Based on the identification of seven waste, the most dominant waste is the defect that is caused by there is no setting of the roll entry guide. The product has 11 CTQ (critical to quality) with the focus on laps defect, underfill defect, and overfill defect. Then, the cause of failure is identified using FMEA (failure mode effect analysis). The level of sigma capability is achieved at 4.54 with DPMO (defect per million opportunities) is 4006.55. The first improvement can reduce the time until 8.9 minutes. The second improvement sets the roll entry guide. The optimum factors for setting of the roll entry guide is A factor with 150 tonnages of wear level, C factor by 5 bar of cooling and D factor by 6 ml of lubrication.

ТЕХНОЛОГИЧЕСКИЕ АСПЕКТЫ ФОРМИРОВАНИЯ КАЧЕСТВА СВАРОЧНОЙ ПРОВОЛОКИ В ТЕХНОЛОГИЧЕСКОЙ СИСТЕМЕ "СТАЛЬ-ПРОКАТКА КАТАНКИ-ВОЛОЧЕНИЕ"

ТЕХНОЛОГИЧЕСКИЕ АСПЕКТЫ ФОРМИРОВАНИЯ КАЧЕСТВА СВАРОЧНОЙ ПРОВОЛОКИ В ТЕХНОЛОГИЧЕСКОЙ СИСТЕМЕ "СТАЛЬ-ПРОКАТКА КАТАНКИ-ВОЛОЧЕНИЕ"

Research on the Solid Solution Behavior of Titanium Inclusion for the High Strength Tire Cord Steel

In order to improve the quality of the cord steel wire rod and achieve the effective control of titanium inclusion, the solid solution behavior of titanium inclusion in tire cord steel during the heating process was discussed in this paper, through the thermodynamic theory analysis, combined with the CLSM experiment. The conclusions are as follows: 1) According to the law of Ostwald repening, the coarsening rate of titanium carbonitride inclusion is very small, the coarsening behavior of titanium carbonitride inclusion cannot be considered in the heating and holding stage. 2) The solid solution behavior of titanium inclusion in the heating process is obviously existed. 3) Through the proper control of rolling temperature, holding time and the subsequent cooling rate, the size and quantity of large particle titanium inclusion in the high strength tire cord steel can be effectively controlled.

Detection of an axial surface microcrack in steel wire rods with noncontact ultrasonic reverberation spectroscopy

In the manufacturing process of steel rod, a number of micro-scale defects occur along the axial direction on the surface of the rods. To prevent failures in advance, a method to detect the micro-scale cracks remaining on the surface of rod is required. This work employs an Electromagnetic acoustic transducer (EMAT) to evaluate the cracks of the wire rods with the noncontact Ultrasonic reverberation spectroscopy (URS). The resonance at the cross section of the cylindrical rods is generated by horizontally polarized shear waves driven in the circumferential direction. Through a series of URS experiments, changes in the resonant frequency, the amplitude of the resonant peak, and the attenuation of the ultrasonic reverberation were observed at intact and defected parts of specimens. The results showed that the URS technique may be one of the effective tools to detect the axial surface microcrack with its depth of a few tens of micrometers.

Experimental Analysis of Residual Stresses in Pre-Straightened SAE 1045 Steel

This paper aims at analyzing the effects of the roller pre-straightening of wire-rods on residual stress distributions in SAE 1045 steel bars. The combined drawing process is used in industrial production of bars in order to obtain a good surface quality and improved mechanical properties complying with specifications of the final products. In this process, prior to the drawing step, a roller straightening of the steel wire-rod is essential, because it provides the minimum straightness necessary for drawing. Metallographic analysis and hardness test were done for selected samples after different processing steps. Also, residual stress analysis of pre-straightened wire-rods by X-ray diffraction and neutron diffraction were carried out. The hardness tests show higher values near the surface and lower in the center of the wire-rod. Besides, the residual stresses results show a big inhomogeneity from one peripheral position to another and also in the evaluated cross section.

Selected Problems of the Microstructure Evolution During Microalloyed Steel Wire Rod Production Process

AbstractIn the present study, we have discussed the selected problems of microstructure development during the whole manufacturing process, i.e. continuous casting, thermomechanical processing, and cold metal forming of the microalloyed steels wires. In the investigated steels, the microstructure development was controlled by the history of deformation and by the effects of microalloying elements, mostly Nb, Ti, and B. It has been concluded that obtained in the ultrafine grained microalloyed steel wires mechanical properties were first of all resulting from specific structural composition and grain refinement. Additionally, it has been proven that austenite grain refinement, that increases nucleation rate during the austenite-to-ferrite phase transformation, as a result of the thermomechanical processing, are very beneficial from point of view of the final mechanical properties. This problem starts to be very important when the microalloyed steel products are subjected to severe plastic deformation, as it has been shown discussed in the present work for combined processes of wire drawing and wire flattening.

A three-dimensional mathematical model to predict air-cooling flow and temperature distribution of wire loops in the Stelmor air-cooling system

Controlling the forced air cooling conditions in the Stelmor conveyor line is important for improving the microstructure and mechanical properties of steel wire rods. A three-dimensional mathematical model incorporating the turbulent flow of the cooling air and heat transfer of the wire rods was developed to predict the cooling process in the Stelmor air-cooling line of wire rolling mills. The distribution of cooling air from the plenum chamber and the forced convective heat transfer coefficient for the wire loops were simulated at the different locations over the conveyor. The temperature profiles and cooling curves of the wire loops in Stelmor conveyor lines were also calculated by considering the convective heat transfer, radiative heat transfer as well as the latent heat during transformation. The calculated temperature results using this model agreed well with the available measured results in the industrial tests. Thus, it was demonstrated that this model can be useful for studying the air-cooling process and predicting the temperature profile and microstructure evolution of the wire rods.

Posco, Finex, and Technology Sharing

POSCO was a South Korean company that manufactured and sold products such as hot-rolled and cold-rolled steel, stainless steel plates, wire rods, and silicon steel sheets. Determined to find a greener and more cost-efficient alternative technology for steelmaking, POSCO decided to develop a new technology. Called FINEX, this technology significantly lowered operating costs, cut emissions, and, by eliminating the need for sinter and coking plants, significantly reduced overall construction costs. Once FINEX proved to be a successful technology, POSCO faced the question of whether and how to share FINEX with its competitors. Company leadership knew that POSCO had only succeeded—indeed, had only come into existence—with the help of other steelmaking companies that had shared their technology, knowledge, and expertise. This would be the first time in POSCO's existence that it would share such a strategic technology with others. The question was, should it share? Excerpt UVA-E-0395 May 7, 2014 POSCO, FINEX, AND TECHNOLOGY SHARING POSCO, originally called Pohang Iron and Steel Company, was a South Korean steelmaking company founded in 1968 by the government in an effort to create an industrial infrastructure. The company, which manufactured and sold products such as hot-rolled and cold-rolled steel, stainless steel plates, wire rods, and silicon steel sheets, had been privatized in the 1990s. By 2012, POSCO was the third-largest steelmaker in the world by volume and the largest based on market capitalization. It was also recognized by Fortune magazine as the most admired metals company in the world. In 2012, POSCO produced 35.5 million tons of steel, had $ 59.58billion in revenues, and earned a net income of $ 2.23 billion. See Exhibit 1 for a financial snapshot of the company. Headquartered in Pohang, South Korea, POSCO had approximately 55,000 employees (including those employed by subsidiaries) and, in addition to Korea, operated in North America, India, Japan, China, and elsewhere in the Asia-Pacific region. Roughly 58% of its steel output was used in Korea for, among other things, shipbuilding and automotive manufacturing—the rest was exported to more than 60 countries. Steelmaking and Its Effects on the Environment In the early 1990s, POSCO had the traditional problem that steelmaking companies faced: the business was tremendously destructive to the environment. Practically every step of the process produced air emissions composed of volatile organic compounds such as carbon monoxide and sulfur and nitrogen oxides. Wastewater generated in the steelmaking process contained high levels of contaminants. While not as toxic as the wastewater, solid waste was generated in enormous quantities. Finally, the steelmaking process consumed tremendous amounts of energy, thus contributing to greenhouse gas emissions. . . .

Posco and Quick Six Sigma

POSCO was a South Korean company that manufactured and sold products such as hot-rolled and cold-rolled steel, stainless steel plates, wire rods, and silicon steel sheets. Along with other steelmaking companies, it faced the dilemma of the excessive waste inherent in its industry. In 2005, POSCO had initiated QSS (Quick Six Sigma or Quick and Smart Solution), which was extremely successful and had continuously contributed to waste reduction. Having achieved laudable goals, including overall efficiency in its workplace environment, was there a way that POSCO and Chung could use the QSS program to help the community and society at large? Excerpt UVA-E-0396 May 7, 2014 POSCO AND QUICK SIX SIGMA POSCO, along with other steelmaking companies, faced the dilemma of the excessive waste inherent in its industry. Byproducts of steelmaking included slag—waste matter that was separated from metals during the smelting or refining process—dust, and sludge. Depending on the specific process used, production of one ton of steel could result in anywhere from 440 to 881 kilograms of byproducts. In addition, industry waste included machine breakdown and malfunction (e.g., oil leakage, belt disconnects, and overloading). In 2005, POSCO had initiated QSS (Quick Six Sigma or Quick and Smart Solution), which was extremely successful and had continuously contributed to waste reduction. Since then, QSS had become the symbol of a culture of improvement in manufacturing. For instance, in 2012, POSCO's coking plant reduced costs by about $ 800,000 by improving machinery performance and reducing malfunction rates through QSS activities. In 2009, POSCO Chairman Joon-yang Chung, intrigued by the effectiveness of QSS within the company, expressed an interest in using it to help POSCO's various stakeholders, including employees, customers, investors, partners, and the community. How could QSS, which had been applied to the logistics and mechanics of the steelmaking factories, be applied to the local community, or even society at large? Could this tool be transferred successfully from the production line to the stakeholders beyond the factory walls? POSCO . . .

Dynamic strain aging during wire drawing and its effect on electrochemical behaviour

Second stage dynamic strain aging is observed during cold drawing of low carbon steel wire rods with higher free nitrogen content. The effect is prominent in thinner wires which have experienced higher strain and are thereby heavily stressed. Consequently, these severely deformed wires with higher nitrogen content are prone to early environmental degradation.

Occurrence of two-stage hardening in C-Mn steel wire rods containing pearlitic microstructure

The 8 and 10 mm diameter wire rods intended for use as concrete reinforcement were produced/ hot rolled from C-Mn steel chemistry containing various elements within the range of C:0.55-0.65, Mn:0.85-1.50, Si:0.05-0.09, S:0.04 max, P:0.04 max and N:0.006 max wt%. Depending upon the C and Mn contents the product attained pearlitic microstructure in the range of 85-93% with balance amount of polygonal ferrite transformed at prior austenite grain boundaries. The pearlitic microstructure in the wire rods helped in achieving yield strength, tensile strength, total elongation and reduction in area values within the range of 422-515 MPa, 790-950 MPa, 22-15% and 45-35%, respectively. On analyzing the tensile results it was revealed that the material experienced hardening in two stages separable by a knee strain value of about 0.05. The occurrence of two stage hardening thus in the steel with hardening coefficients of 0.26 and 0.09 could be demonstrated with the help of derived relationships existed between flow stress and the strain.

Corrosion of Carbon Steel Wire Roads Containing Various Sulfur Content in Sour Solutions

High strength carbon steel wire roads have been widely used in armor cables for offshore oil drilling plants. However, the materials can undergo some corrosions and hydrogen related damages such as hydrogen induced cracking (HIC) and sulfide stress cracking (SSC). In particular, it has been reported that HIC is highly influenced by content of MnS containing inside the steels. However, effects of sulfur content on the corrosion of carbon steel wire rod have scarcely been reported systematically. In this study, the effects of sulfur and propagation of corrosion in carbon steel wire rod were investigated in sour solutions with various pH. The carbon steel wire rods containing various sulfur content were used. All electrochemical tests were conducted using three-electrode system with a saturated calomel electrode (SCE) as the reference electrode and a Pt wire as the counter electrode. In addition, acetic acid based solution containing 95% CO2 and 5% H2S were used to adjust pH in the range of 2.5-6.5 at the room temperature for corrosion tests. Before testing, the carbon steel wire words were polished by abrasive papers and then washed with ethanol, and deionized water. The overall corrosion behaviors and corrosion rate of the samples were analyzed using potentiodynamic tests. In addition, the HIC characteristic of the steels was investigated by immersing the samples in the solution followed by observing the crack propagation inside the samples. Surface morphologies of the samples after tests were also observed by optical microscope (OM) and scanning electron microscope (SEM). The corrosion current densities (icorr ) of carbon steel increased with the increasing in sulfur contents in the steels. Further, from the polarization curves, it is observed that cathodic current density increased with sulfur content in steels. It is noticeable that the anodic current density rarely changes. This result indicates that the cathodic hydrogen evolution process on the surface of the steels was promoted by S content inside the steels. In addition, the samples without applied stress showed the internal macro-cracks in cross sections in pH 2.5~5.1, while only small micro-cracks were found in solution pH 5.1~6.5. The length of crack increased with increasing sulfur content except in the solution with pH 5.1~6.5. In particular, the micro-cracks by HIC appeared to initiate around inclusions. Some tracing of the cracks will be shown in this presentation.

The Assessment of the Cold Plastic Workability of 20MnB4 Steel Wire Rod / Ocena Zdolności Do Przeróbki Plastycznej Na Zimno Walcówki Ze Stali 20MnB4

The paper presents the results of cold upsetting testing of 16.5 mm-diameter 20MnB4 steel wire rod. The main purpose of the study was to evaluate the ability of wire rod produced in industrial conditions for further cold metal forming. Due to the fact that cracks occurred in the test material at different strain values, the authors made an attempt to answer the question whether there are any crack initiators in the material structure, or the observed cracks are due to the manufacturing process parameters. In order to determine the causes of cracks appearing during upsetting tests, micro- and macroscopic observation techniques were used. For the macroscopic examination, an Olympus SZ-31 microscope was used, while a Nikon Ma-200 microscope was employed for the microscopic examination. The microscopic examination was carried out both in a light and dark fields. To evaluate the effect of surface topography on the crack formation tendency, the results of macroscopic observation under a magnification from 6.7x to 45x were used.