scholarly journals Study of the process of rolling steel balls in skew rolling mill – metallographic analysis

2021 ◽  
Vol 24 (1) ◽  
Author(s):  
Piotr Chyła
Keyword(s):  
Rolling Mill ◽  
Rolling Process ◽  
Dark Field ◽  
Bearing Steel ◽  
Metallographic Analysis ◽  
Modified Method ◽  
Microscopy Technique ◽  
Cooling Media ◽  
Steel Balls ◽  
Skew Rolling

This paper presents the results of metallographic research studies carried out for stock materials as well as the samples collected from the balls formed in the rolling process in a skew rolling mill. The stock material was bearing steel 100Cr6 and the steel from rail scrap. The rolling process was carried out in parallel for the two assumptions: the conventional method (hereinafter referred to as conventional rolling) and the modified method (hereinafter referred to as modified rolling). After the rolling process, three cooling media were used: air, water and oil. The pictures below, which depict microstructures, were taken using the bright-field and the dark-field microscopy technique, the samples were etched with a 4% solution of picral.

scholarly journals A COMPUTER SYSTEM FOR ACQUISITION AND ANALYSIS OF MEASUREMENT DATA FOR A SKEW ROLLING MILL IN MANUFACTURING STEEL BALLS

2020 ◽  
Vol 10 (4) ◽  
pp. 47-50
Author(s):  
Marcin Buczaj ◽  
Andrzej Sumorek
Keyword(s):  
Data Acquisition ◽  
Computer System ◽  
Rolling Mill ◽  
Measurement Data ◽  
Rolling Process ◽  
Physical Parameters ◽  
Main Task ◽  
Technical Parameters ◽  
Steel Balls ◽  
Skew Rolling

The article presents the concept and capabilities of a computer system for analysing measurement data for a skew rolling mill used to produce steel balls. The computer system for data acquisition and analysis consists of cooperating systems designed to perform control and measurement tasks during the operation of a skew rolling mill. Their main task is to collect and record data related to the measured physical parameters of the batch rolling process. This system registers the current and analyses the radial forces and torque acting on the rolled element by the rolling tool. The process of data acquisition, analysis and archiving is carried out by means of an NI USB 6009 measuring card together with the attached systems of transducers and force and torque sensors and a computer with an installed application. The measurement application was developed in the LabVIEW environment. The application algorithm is based on the state machine architecture and enables the configuration of measurement elements and technical parameters, checking the functioning of the control and measurement system and the acquisition and archiving of measurement data.

Effects of structural inhomogeneities on the steel balls resistance to loading

2020 ◽  
pp. 29-38
Author(s):  
O. B. Berdnik ◽  
I. N. Tsareva ◽  
L. A. Krivina ◽  
S. V. Kirikov ◽  
S. I. Gerasimov ◽  
...  
Keyword(s):  
Brittle Fracture ◽  
Bearing Steel ◽  
Metallographic Analysis ◽  
Structural Factors ◽  
Steel Shkh15 ◽  
Maximum Hardness ◽  
High Shock ◽  
Steel Balls ◽  
Plasticity Coefficient ◽  
Microstructure Of The Material

When conducting impact tests of protective glasses, nonunique cases of destruction of balls made of bearing steel ShKh15 were recorded. The causes of their destruction were determined. The state of the material was studied by fractographic and metallographic analysis, hardness and microhardness measurement. In the structure of the metal of all the balls, no critical defects were found such as flockens, shells and microcracks, but adverse factors were detected in the microstructure of the material, namely, the presence of fineneedle martensite with excessive carbides. It is established that the detected structural factors lead to liability to brittle fracture, an increase in the hardness of the material, a decrease in plasticity. To prevent brittle fracture of the balls and provide a reserve of plasticity of steel ShKh15 at high shock loads assessment calculations of ductility coefficient were made; and it was recommended to limit the maximum hardness of the material critical value HV=5.70 HPa (54 HRC), with the corresponding plasticity coefficient equal to 0.8.

scholarly journals The Chosen Aspects of Skew Rolling of Hollow Stepped Shafts

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 764
Author(s):  
Jarosław Bartnicki ◽  
Yingxiang Xia ◽  
Xuedao Shu
Keyword(s):  
Cross Section ◽  
Rolling Mill ◽  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Numerical Control ◽  
Technological Parameters ◽  
Flow Mechanisms ◽  
The Individual ◽  
Skew Rolling

The paper presents chosen aspects of the skew rolling process of hollow stepped products with the use of a skew rolling mill designed and manufactured at the Lublin University of Technology. This machine is characterized by the numerical control of spacing between the working rolls and the sequence of the gripper axial movement, which allows for the individual programming of the obtained shapes of parts such as stepped axles and shafts. The length of these zones and the values of possibly realizable cross-section reduction and obtained outlines are the subject of this research paper. The chosen results regarding the influence of the technological parameters used on the course of the process are shown in the present study. Numerical modelling using the finite element method in Simufact Forming, as well as the results of experimental tests performed in a skew rolling mill, were applied in the conducted research. The work takes into account the influence of cross-section reduction of the hollow parts and the feed rate per rotation on the metal flow mechanisms in the skew rolling process. The presented results concern the obtained dimensional deviations and changes in the wall thickness determining the proper choice of technological parameters for hollow parts formed by the skew rolling method. Knowledge about the cause of the occurrence of these limitations is very important for the development of this technology and the choice of the process parameters.

Influence of the Deformation Method on the Microstructure Changes in AZ31 Magnesium Alloy Round Rods Obtained by the Rolling Process

2016 ◽  
Vol 716 ◽  
pp. 864-870
Author(s):  
Andrzej Stefanik ◽  
Piotr Szota ◽  
Sebastian Mróz ◽  
Teresa Bajor ◽  
Sonia Boczkal
Keyword(s):  
Magnesium Alloy ◽  
Numerical Modelling ◽  
Rolling Mill ◽  
Laboratory Tests ◽  
Effective Strain ◽  
Rolling Process ◽  
Az31 Magnesium Alloy ◽  
Deformation Method ◽  
Microstructure Changes ◽  
Skew Rolling

This paper presents the research results of the microstructure changes of the round rods of AZ31 magnesium alloy in the hot rolling processes. The rolling was conducted in duo mill and a three-high skew rolling mill. Numerical modelling of the AZ31 magnesium alloy round rods rolling process was conducted using a computer program Forge 2011®. The verification of the results of numerical modelling was carried out during laboratory tests in a two-high rolling mill D150 and a three-high skew rolling mill RSP 40/14. Distributions of the total effective strain and temperature during AZ31 rods rolling process were determined on the basis of the theoretical analysis. Microstructure and texture changes during both analysed processes were studied.

scholarly journals Design and technological capabilities of a CNC skew rolling mill

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak ◽  
Konrad Lis ◽  
Tomasz Kusiak ◽  
...  
Keyword(s):  
Rolling Mill ◽  
Performance Test ◽  
Metal Flow ◽  
Fem Analysis ◽  
Rolling Process ◽  
Design Solution ◽  
Test Results ◽  
Rolling Method ◽  
Mill Stand ◽  
Skew Rolling

AbstractResults of a study investigating a skew rolling process for elongated axisymmetric parts are presented. Despite the fact that the skew rolling technique for producing such parts was developed and implemented in the mid-twentieth century, there are no studies on this problem. The first part of this paper presents the results of FEM modelling of skew rolling stepped axles and shafts (solid and hollow). The FEM analysis was performed using the MSC Simufact Forming software. The numerical simulation involved the determination of metal flow patterns, the analysis of thermal parameters of the material during rolling, and the prediction of cracking by the Cockcroft-Latham ductile fracture criterion. Force parameters of rolling solid and hollow parts were also determined. The aim of the FEM analysis was to determine initial design assumptions and parameters for the development of the skew rolling mill. Later on in the paper, a design solution of a CNC skew rolling mill for rolling parts based on their envelope profile is proposed. FEM strength test results of a mill stand, obtained with MSC. NASTRAN, are presented. Finally, the performance test results of the constructed rolling mill are presented. The experiments involved rolling real stepped shafts that were modelled numerically. Obtained results show that the proposed skew rolling method has considerable potential. The designed and constructed rolling mill can be used to perform the rolling process according to the proposed method, with the tool and material kinematics being controlled based on the set parameters of a workpiece envelope.

scholarly journals Theoretical And Experimental Analysis Of Aluminium Bars Rolling Process In Three-High Skew Rolling Mill

2015 ◽  
Vol 60 (2) ◽  
pp. 809-813 ◽  
Author(s):  
A. Stefanik ◽  
A. Morel ◽  
S. Mróz ◽  
P. Szota
Keyword(s):  
Rolling Mill ◽  
Rolling Process ◽  
Theoretical Research ◽  
Rolling Mills ◽  
Good Surface ◽  
Experimental Rolling ◽  
Deformation Stress ◽  
Deformable Materials ◽  
Roll Gap ◽  
Skew Rolling

Abstract Technology of round bars rolling on a three-high skew rolling mills allows rolling of standard materials such as steel and aluminum, as well as new materials, especially hard deformable materials. The paper presents the results of theoretical and experimental rolling process of aluminum bars with a diameter of 20 mm. As the stock round bars with a diameter of 25 mm made of aluminum grade 1050A and aluminum alloy grade 2017A were used. The rolling process of aluminum bars has been carried out in a single pass. The numerical analysis was carried out by using computer program Forge2011®. On the basis of theoretical research it has been determined the state of deformation, stress and temperature distribution during rolling of aluminum bars. In addition, the results of theoretical research allowed to determine the schema of the metal plastic flow in the roll gap. Verification of the theoretical research was carried out during the rolling of aluminum bars on the RSP 40/14 laboratory three-high skew rolling mill. From the finished bars were taken the samples to set the shape and compared with the results of theoretical research. Finished aluminum round bars were characterized by low ovality and good surface quality.

scholarly journals Analysis of the Rolling Process of Alloy 6005 in a Three-High Skew Rolling Mill

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1114 ◽  
Author(s):  
Teresa Bajor ◽  
Anna Kulakowska ◽  
Henryk Dyja
Keyword(s):  
Aluminum Alloy ◽  
Process Simulation ◽  
Rolling Mill ◽  
Strain State ◽  
Rolling Process ◽  
Simulation System ◽  
Metallurgical Process ◽  
Compression Tests ◽  
Skew Rolling ◽  
Numerical Examination

This paper presents the results of numerical modelling of the rolling process of aluminum alloy bars in a three-high skew mill. The purpose of the examination was to determine the optimal rolling temperature for this alloy. The numerical examination for aluminum alloy 6005 (AlZn5.5MgCu) was performed using the Forge3®-2D Plane strain state commercial software. The rheological properties of the examined alloy were determined from uniaxial compression tests done using the metallurgical process simulation system Gleeble 3800. The numerical analysis of the process of rolling 6005 alloy bars in a three-high skew mill was conducted within the temperature range of 150–350 °C and at a deformation of 0.29.

scholarly journals Numerical Analysis of a Rolling Process for Producing Steel Balls Using Helical Rolls

2016 ◽  
Vol 61 (2) ◽  
pp. 485-492 ◽  
Author(s):  
P. Chyła ◽  
Z. Pater ◽  
J. Tomczak ◽  
P. Chyła
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Rolling Force ◽  
Thermal Conditions ◽  
Rolling Process ◽  
The Finite Element Method ◽  
Feed Material ◽  
Modified Method ◽  
Steel Balls

Abstract This paper presents the research results of the balls rolling process according to the conventional and modified methods of rolling. Theoretical analysis was carried out by using numerical methods based on the Finite Element Method. The Simufact package version 10.0 were used for calculation. Simulations of balls rolling were carried out under conditions of 3D state of strain, taking into account the effect of thermal conditions occurring during forming. The study of the achieved results showed that the best rolling process parameters were obtained for the modified method, in which the feed material is heated up to 1150 °C. In this case, the rolling parameters such as: rolling force and torque as well as tool wear reached the smallest values.

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