Piercing Process Research Articles

STUDY OF THE SEAMLESS PIPES PROPERTIES OBTAINED FROM A HOLLOW BILLET

The article researched the influence on the pipes mechanical properties initial billet obtained by the traditional method and the proposed method, in which the piercing process is excluded. The proposed method involves casting the initial billet for the production of seamless pipes with a cavity obtained on a continuous casting machine. The production of hotrolled seamless pipes from a hollow billet is an urgent issue today, since central porosity and axial segregation after casting are excluded, affecting the quality of the pipes obtained in the subsequent stages of production: rolling on a mandrel mill and reducing. The possibility of producing seamless hot-rolled pipes from a hollow billet is substantiated, providing the necessary set of mechanical properties that are regulated by the standards GOST 632-80, GOST 633-80 and API 5CT. The result is a minimal deviation of the mechanical properties of steel samples obtained by double deformation of a hollow continuously cast billet from samples obtained according to the traditional scheme, including the piercing process. Keywords: hollow billet, steel, 09Mn2Si, seamless pipe, piercing process.

Investigation on the principle and performance of fiber optical reflectometer based on wave optics simulation

Fiber optical reflectometer (FOR) is a novel technique for dense droplet detection that combines conventional phase detection with non-invasive velocity measurement capabilities. In this study, the mechanism of FOR technique and its sensitivity to droplet trajectory are investigated by wave optics simulation and experiment. This paper first describes the simulation method and analyzes the dynamic response of probe during the droplet piercing process. Next, an exploration is conducted on the effective field of view for the probe and the detectable interface inclination. Afterwards, by precisely controlling the droplet size, eccentricity, and trajectory, the simulation reveals the sensitivity of FOR technique to droplet parameters and quantifies the accuracy of measurement on droplet velocity, which provides specific guidance for the design and application of FOR technique. Finally, in the static experiment, the measurement error of the droplet axial velocity is controlled within 13 %, which verifies the reliability of the simulation results.

Technology Optimization Analysis of Three-Roll Rotary Piercing Process for Seamless Steel Pipe

Technology Optimization Analysis of Three-Roll Rotary Piercing Process for Seamless Steel Pipe

Effect of Three-High Rotary Piercing Process on Microstructure, Texture and Mechanical Properties of Magnesium Alloy Seamless Tube

Effect of Three-High Rotary Piercing Process on Microstructure, Texture and Mechanical Properties of Magnesium Alloy Seamless Tube

Implementation of Continuous Improvement to Increase the Efficiency of the Production Process through Press Dies Design

In the manufacturing industry, there are companies that operate in the metal forming sector. Many products are produced by the metal forming process, one of which is the packaging box lock hook. The key hook is a component part of the packaging box which functions as a hook so that the packaging box can be closed and locked. In the production of key hooks there is waste, namely over processing, which reduces the efficiency of production time. To reduce this problem, improvement efforts were made by implementing continuous improvement using the DMAIC method. Continuous improvement steps are carried out by direct observation in the field to find problems. After that, measurements and analysis are carried out to determine improvements that will be implemented. Then the improvement stage was carried out as an implementation of continuous improvement. Continuous improvement resulted in a press dies design for the key hook piercing process. By designing new press dies, production time efficiency will be achieved. After carrying out Continuous Improvement, it resulted in an increase in the efficiency of the number of processes from 6 processes to 5 processes and the total production time in 1 cycle from 13.3 hours to 11.4 hours or 1.9 hours faster or an increase in efficiency of 13.3 % of the total time before Continuous Improvement. And 50% increase in sub piercing process.

PLASTIC DEFORMATION WITH OPEN STITCHING. DETERMINATION OF PROCESS PARAMETERS

Examples of determining the main parameters of the piercing process and comparing the calculated results with numerous experimental data are presented, confirming the high accuracy of the developed theory of piercing.

Study of the process of press piercing of billets and development of technological measures to reduce defect formation in the area of pressing-out failure

Study of the process of press piercing of billets and development of technological measures to reduce defect formation in the area of pressing-out failure

Analysis of super Cr13 stainless-steel internal fracture growth effects during skew mill piercing process

The seamless tube piercing process of super Cr13 martensitic stainless steel is addressed in this paper by comparing industrial piercing tests, laboratory hot tensile tests for material behavior characterization, and finite element simulations. Particular focus is given to the effect of process parameters on internal fracture growth and geometrical homogeneity of the tube. The geometrical non-homogeneities found on industrial pierced tubes are closely related to the change of flow stress of super Cr13 stainless steel during the piercing process. This way, the non-uniform strain rate along the tube's cross-section during piercing affects the fracture growth and, consequently, the thickness homogeneity of the tube, which varies from tip to tail. Due to obtained results, the mean value of pierced tube perimeter is 660 mm, while the mean value of the tube perimeter in the FEM simulation was predicted to be 2 % more (675 mm). The contact temperature of the plug and piercing tube was predicted at 1100 °C, and the mean value of pierced tube diameter in the simulation (210 mm) was 1.5 % more than the mean value of the actual tube (207 mm). The morphology of δ-ferrite affects the origin of primary crack initiation during the piercing process. Short and thick grains of δ-ferrite created at low strain rates that lengthen with increasing strain rate affect fracture sensitivity at the tip of the plug, favoring the non-homogeneity of the material.

Compression-shear fracture of nickel-based superalloy during rotary tube piercing

Large-diameter nickel-based superalloy seamless tubes are the key component of pipeline transmission system in nuclear power, thermal power and petroleum industries. The rotary tube piercing (RTP) process is suitable to prepare large-diameter seamless tubes. However, the high temperature dynamic compression-shear fracture, also known as separation layer defect (SLD), is inevitable in the RTP process of nickel-based superalloy. In the study, the SLD was systematically studied by the combination of simulation and experiment. Firstly, the isothermal compression-shear experiments were designed to study the fracture behaviors. The results reveal that the plasticity of Inconel 718 alloy decrease with the increase of temperature and strain rate within the range of temperature 1080-1160℃ and strain rate 5–40/s, and the shear angle has significant effects on the fracture behavior. Secondly, based on the isothermal compression-shear experiment results, the SLD was explored by RTP experiments. The results reveal that the compression-shear deformation extent has significant effects on the SLD, and the folding defect is generated before the SLD is observed. The fracture morphology further confirms that the SLD belongs to typical shear fracture, which is generated under specific strain and stress state. Finally, the formation mechanism of SLD is revealed by combining finite element simulation and experiment. It is found that the formation of SLD includes crack initiation and crack propagation. Crack initiation is related with the maximum shear strain and maximum shear stress, and the crack propagation is controlled by radial deformation gradient.

PLASTIC DEFORMATION WITH OPEN STITCHING. CONCAVITY OF THE UPPER END OF THE WORK PIECE

A theoretical description of the formation of concavity at the upper end of the work piece at the beginning of the piercing process is obtained. The established analytical dependences make it possible to calculate the maximum depth of the resulting concavity. The high accuracy of the calculated data is confirmed by comparison with known experimental data.

Effect of a Zn interlayer on the formation mechanism and mechanical performance of AA6061/DP590 steel resistance riveting welding

This study focuses on the forming mechanism of resistance riveting welding joints of 6061 Al alloy and DP590 steel plate and the effect of adding Zn interlayer on the mechanical properties of the joints. During the piercing stage, the rivet pierces through the Al plate, the Al plate beneath the rivet melts and reacts with the steel, with intermetallic compounds (IMC) generated. Some of the melted Al and IMCs are squeezed onto the side of the rivet. In the process of adding the Zn interlayer, the Zn is gradually incorporated into the melted Al near the rivet during the piercing process. At the welding stage, as the current is increased, the nugget diameter, peak joint load, and energy absorption values gradually increase. The failure mode of the joint changes from an interfacial fracture to pull-out fracture, eventually changing to base material pull-off, as the welding current increases. Compared to joints without Zn addition, joints with Zn addition exhibit a smaller nugget diameter, and narrower IMC layers at the interface. At a welding current of 13 kA, because the failure mode was a shear fracture of the nuggets, the peak joint load of the joints with zinc added decreased by 215 N compared to the unadded ones. On the contrary, when the current increased to 14 kA, the peak joint load of the joints was elevated by 639 N, because the IMC layer and the aluminum plate became the main load-bearing locations.

Physics-informed graph neural networks accelerating microneedle simulations towards novelty of micro-nano scale materials discovery

To commercialize the micro-nano needle as a drug delivery or biosensing platform, it is essential to validate the effectiveness and reliability of the piercing process for each needle material composition. However, proper microneedle material selection and fabrication requires sophisticated and costly semiconductor technology. This work aims to accelerate the material selection process of microneedles, focusing on polymeric materials due to their biocompatibility and flexibility. In this study, simulations of microneedles with various materials are used to generate training and testing data for a physics-informed machine learning model to predict von Mises stress distribution on microneedles of new materials. The training dataset is comprised of results from fifteen different materials. Different machine learning models are used, such as traditional tree-based, neural network, point cloud network, and graph-based models. Random-index selection is utilized to reduce the required number of data points by an order of magnitude. The graph attention network model is the best-performing model for predicting the von Mises stress of microneedles, with a mean square error of 8.3×10−5MPa. The resulting model only requires 7 ms to evaluate a new microneedle material, significantly faster than practical fabrication in a laboratory. The models also successfully handle data with a decimal scale obtained from microstructure simulations and predict physical behavior such as stress curves.

Development of a computer program for calculating the geometric parameters of the deformation zone and mill tuning parameters in the process of producing hot-rolled seamless tubes

Determining the optimal tuning parameters for a piercing mill is a labor-intensive process. There are various calculation methods available for determining the tuning parameters of a piercing mill but implementing these methods can be time-consuming. Therefore, the developed computer program for calculating the geometric parameters of the deformation zone during the piercing of round billets and the tuning parameters of the piercing mill represents an innovative tool for calculating the tuning parameters of the piercing mill. The program allows for the establishment of optimal parameter values required to achieve the desired quality and accuracy of the steel piercing process. The main functions of the program include the analysis and processing of input data, such as the billet diameter, steel grade, roll calibration, and piercing mill tools. Based on this data, the program utilizes a developed mathematical model to calcu-late the optimal tuning parameters of the piercing mill, considering the required process characteristics and the desired level of product quality. One of the key features of the program is its high accuracy and universality. It takes into con-sideration multiple factors that affect the piercing process and enables reliable production forecasting. The program has a user-friendly interface, making it convenient for both specialists and shop floor personnel in the field of hot-rolled seamless tube production. The developed computer program is a valuable tool for manufacturers and research centers involved in steel piercing. It helps improve production efficiency, enhance product quality, and reduce time and costs associated with piercing mill setup. The program represents a significant contribution to the development and improve-ment of piercing technology in industrial settings

Effects of skew rolling piercing process friction coefficient on tube twisting, strain rate and forming velocity

In this paper the effects of rollers-billet friction coefficient (RFC) and plug-billet friction coefficient (PFC) during the skew rolling piercing process are investigated. The piercing process has been simulated and the plastic deformation, temperature evolution, and surface twisting of pierced tube analysed. Results show that the plastic deformation of super-martensitic Cr13 stainless steel increases at higher RFC and decreases at higher PFC. The same trend has been observed for material strain rate, which increases with higher RFC but decreases with increasing PFC. In addition, it has been found that friction coefficient does not affect the temperature evolution of the billet. In fact, the material heating during piercing is related to plastic deformation. Comparison of the fracture surfaces of the hot tension test samples at 0.01 s−1 and 10 s−1 confirm this point. The RFC increases the forward material velocity, and PFC decreases the forward material during the skew rolling piercing process. The PFC decreases the material velocity due to the ductile fracture growth obstacle inside the tube. More plastic deformation at higher PFC leads to higher surface twisting. The maximum surface twisting was 68° at RFC = 0.6 and PFC = 0.06, and the minimum surface twisting was 12° at RFC = 0.2 and PFC = 0.15.

Programmable Controller Based Piercing Machine System Design

The former mainly consists of solenoid valve actuators, sensors, programmable controllers, etc. The core of the hardware design is PLC and related wiring design; the latter is mainly through Protherm V14 to complete the programming, based on the overall architecture of the system to complete the ladder design of subroutines, program flow analysis is the software design is the focus of the final successful design of the electrical control system of the piercing machine. After system debugging and testing, the system has successfully achieved the expected goal and can meet the user's control requirements with simple and clear control logic, which can meet the mechanical piercing process requirements.

A Method for Measuring the Inclination of Forgings Based on an Improved Optimization Algorithm for Fitting Ellipses

During a piercing or punching process, the center axis of a forging stock is required to be parallel to the direction of movement of the upsetting rod or piercing needle because any small tilt of the stock will cause uneven upsetting or uneven punching wall thickness. In order to detect the inclination of a stock during forging, a method for measuring the inclination of forgings based on an improved optimization algorithm for fitting ellipses is proposed in the work. Specifically, a laser rangefinder is used to measure the distances to the surface of the workpiece, which are converted into Section profile coordinates through coordinate transformation. Next, the randomly divided area and random sampling are presented for screening data points, making it possible to effectively eliminate the influence of abnormal values in the measurement points. Then, taking the point-to-ellipse orthogonal distance as the geometric model, we propose an improved particle swarm optimization (PSO) algorithm to solve the target ellipse parameters. Subsequently, we compare the fitting effect with four other contemporary advanced methods to verify the superiority of the algorithm in ellipse fitting. Finally, the three-dimensional linear equation of the center axis of the forging stock is obtained according to the center point of the long axis of the ellipse in the vertical direction, and the inclination angle of the forging stock is calculated according to the linear equation. The experimental measurement reveals that the error that occurred using the method is less than 0.05°.

Effect of Top Sheet Materials on Joint Performance of Self-Piercing Riveting

Three types of self-piercing riveting (SPR) joints, i.e., steel/aluminum, carbon fiber reinforced polymer (CFRP)/ aluminum, and aluminum/aluminum, were constructed using three different top sheet materials with the same aluminum alloy as the bottom sheet. The effects of the top sheet material on the joint quality and mechanical behavior were evaluated. The top sheet materials’ characteristics dominate the rivet piercing process and the consequent interlock distance. The high-strength steel top sheet requires a comparatively higher rivet setting force and induces early flaring of the rivet tail, resulting in a larger interlock distance. Though the CFRP needs the highest rivet setting force to penetrate the rivet through the CFRP fibers, the CFRP/aluminum joint exhibits the smallest interlock distance because of the SPR process-induced damages to the CFRP and subsequently less flaring of the rivet tail. In strength tests, the damaged CFRP sheet resulted in rivet head pullout of the CFRP/aluminum joints, which exhibited the lowest lap-shear and cross-tension strengths. In contrast, the steel/aluminum joints demonstrated the highest strengths because of their comparatively larger interlock distances. In addition to the experimental analysis, simulations revealed the rivet penetration and flaring mechanisms with various top sheet materials, and their respective joint quality and strengths.

MODELLING OF MATERIAL FLOWS IN PIERCING TECHNOLOGY

The article summarises the modelling of the technological process of Mannesmann piercing in the configuration of the GreatMannesmann rolling mill in the Tube Mill of Třinecké Železárny using the approach of both mathematical modelling and numerical simulation. In accordance with the mathematical model of the given process, the formation of the cavity during the rolling in the numerical range is replaced by pre-drilling a billet of a specific size given by the mathematical model. The numerical simulations have shown an absolutely fundamental effect of the distribution of the initial temperature field of the billet on the actual piercing process. The billet with the initial inhomogeneous temperature field was subject to very strong transverse oscillations and significant spiral structures appeared in the distribution of all physical quantities. When simulating the piercing process on the Mannesmann piercer in the Tube Mill of Třinecké Železárny, parameterised by a mathematical model so as to take into account in the best possible approximation the influence of the cavity initiation sequence during the actual piercing, the simulation results were completely consistent with the predictions of the mathematical model of the submitted process calibration.

Developing a Real-Time Working Method That Improves Process Efficiency in High-Power Fiber Laser Systems.

The need for studies on new simulation and monitoring methods for interactions occurring during material processing in high-power fiber laser systems has increased. In this manuscript, a structure that can intervene in real time and improved solutions that demonstrate the potential of photodiode-based monitoring are presented. By processing the signals instantly received during material processing with InGaAs and Si photodiodes integrated into the cutting head in algorithms, the method that intervenes in the process by detecting the last stage of the piercing process and the problems that may occur during cutting are explained. The stability of the proposed system has been tested on the most used materials in the industry such as St37, stainless steel, and aluminum at laser powers of 6, 8, and 10 kW, respectively. In this article, it is shown that there is a relationship between the signals observed in the infrared (IR) and visible (VIS) spectrum and the characteristics of the cut quality and scenario. Analysis results of photo-diode tracking signals obtained according to material, power, and gas type are presented. Among the innovations added by the method are related application process improvements, material analysis, and cutting and piercing parameter improvements.

Morphological adaptations of the mouthparts to the ectoparasitic lifestyle of the biting midge Forcipomyia paludis (Diptera: Ceratopogonidae), specialized in Odonata

Damselflies and dragonflies are well-known hosts of the West Palaearctic biting midge Forcipomyia paludis. Females of this ectoparasitic dipteran mainly cling to the host’s wings, sucking hemolymph from the wing veins. The midges are firmly attached to the wing surface with specialized tarsi, thus not being flung away during the host’s flight maneuvers. As for another ceratopogonid—F. odonatophila from New Guinea—had been suggested, we assumed that in F. paludis, the attachment would be reinforced by the mouthparts during the suction action. In the present study, we used behavioral field observations, scanning electron microscopy (SEM) and high-resolution micro-computed tomography (µCT), to study the mouthparts of F. paludis. We focused on the mouthpart configuration post sucking and thus on the contact with the host's wing as well as on the piercing process into the wing veins. We foster our understanding of F. paludis being a parasite of Odonata by showing proof of the piercing and therefore the sucking of hemolymph from the wings. Additionally, the mouthparts clearly show contamination with odonate wing wax after the sucking procedure. Furthermore, we discuss probable additional functions of the piercing process for the firm attachment to the flying host of F. paludis.