scholarly journals Influence of the Initial Cast Structure on the Quality of Hot Rolled Hypoeutectoid Steel

2021 ◽  
Vol 19 (1) ◽  
pp. 48-59
Author(s):  
A.A. Khlybov ◽  
◽  
E.L. Vorozheva ◽  
Keyword(s):  
Cast Structure ◽  
Hot Rolled ◽  
Hypoeutectoid Steel

Effects of the microstructure of twin roll cast and hot rolled plates on the surface quality of presensitized plates

2014 ◽  
Vol 21 (9) ◽  
pp. 919-924
Author(s):  
Yuan-Zhi Zhu ◽  
Ya-Feng Zhang ◽  
Chao-Qi Zhao ◽  
Feng Zhou
Keyword(s):  
Surface Quality ◽  
Twin Roll Cast ◽  
Hot Rolled ◽  
Twin Roll ◽  
Rolled Plates

Quality Control of Casting Slab for 510L Steel

2011 ◽  
Vol 117-119 ◽  
pp. 756-759
Author(s):  
Hong Pan ◽  
Guo Rong Wu ◽  
Zhi Qiang Li
Keyword(s):  
Continuous Casting ◽  
Working Condition ◽  
Steel Plate ◽  
Rolled Sheet ◽  
Mold Powder ◽  
Continuous Casting Slab ◽  
Narrow Side ◽  
Corner Cracks ◽  
Hot Rolled

Slab quality affects the quality of hot rolled sheet significantly. There were serious transverse corner cracks on continuous casting slab of 510L steel plate in Panzhihua Steel before. Based on this, some effective countermeasures are put forward, such as the optimization of ratio of heat flux on narrow side and broad side of casting slab and mold powder, as well as the stabilization of casting speed and working condition of caster. With these countermeasures, transverse corner cracks on continuous casting slab have been significantly reduced, and the lines and peeling defects on hot rolled sheet reduce from 30% to 0.

Quality of seamless hot-rolled pipe, taking account of mandrel oscillations

2009 ◽  
Vol 39 (1) ◽  
pp. 72-75 ◽  
Author(s):  
V. N. Danchenko ◽  
S. R. Rakhmanov
Keyword(s):  
Hot Rolled ◽  
Rolled Pipe

Modelization of the Rolling Mill with a FE Code

2015 ◽  
Vol 651-653 ◽  
pp. 291-296 ◽  
Author(s):  
Damien Chevalier ◽  
Pierre Cezard ◽  
Laurent Langlois ◽  
Régis Bigot
Keyword(s):  
Process Parameters ◽  
Production Line ◽  
Rolling Mill ◽  
Production Costs ◽  
Internal Quality ◽  
Industrial Data ◽  
Rolled Material ◽  
Major Factors ◽  
Hot Rolled

To reduce production costs and to improve performances of hot rolled products, it is necessary to optimize the production line. The rolling mill is one of the major factors which affect the internal quality. In fact the process tends to reduce the size of defects during the strain. The production line consisting of 24 stands has been modeled with a commercial FE-code FORGE®. First, a model has been developed and adjusted according to industrial data. Then a parametric study was carried out in order to estimate the influence of the process parameters on the internal quality of the rolled material.

scholarly journals Transformation of cross cracks of continuously casted billet in rolled product

2019 ◽  
Vol 75 (8) ◽  
pp. 930-935
Author(s):  
N. A. Glazunova ◽  
S. V. Stefanovich ◽  
V. S. Puteev
Keyword(s):  
Rolled Product ◽  
Surface Defects ◽  
Multiple Cracks ◽  
Crack Location ◽  
Product Surface ◽  
The Cross ◽  
Hot Rolled ◽  
Discontinuity Flaws

Increased requirements to the surface quality of hot-rolled products used in automobiles manufacturing and endeavor to decrease t rejections of the metal with surface defects, stipulate the necessity to increase the quality of the initial continuously casted billet (CCB). Cracks, formed in the process of crystallization, which are transformed into surface defects of rolled products during hot deformation are attributed to the surface defects of CCB. Classification of defects presented, reasons of cross cracks on CCB and their locations considered. In the course of the experiment the samples, cut from two CCBs in the place, where cross cracks were visually revealed after shot blasting and hot etching in the 50% solution of chloric acid. The cross cracks on the surface of a sample were revealed in the zone of the big side, and the other – on a rib. The longitudinal polished sections were cut from the place of cross cracks location. At the study of the polished sections multiple cracks were discovered. The width of cracks opening was different – from 0.01 up to 0.3 mm, depth in the section of the study – up to 10 mm. The locations of the cross cracks on the billets were marked by notches from two sides (method of “marked” defects). After that the billets were rolled at a one-stand reversible mill 850 for the diameter of 100 mm. At the visual inspection of the rolled product surface, obtained from the defect CCB, surface defects in the form of discontinuity flaws were discovered. The discontinuity flaws looked as metal ruptures of longitudinal and cross orientation and sometimes having a form of tongue. The degree of defects development depends on the depth and the crack location on the initial CCB. The defects which location corresponds to the CCB side have less opening, and defects which location corresponds to the initial billet rib looked as a rough fissure. Cross samples were cut in the places of defects locations on the surface of rolled product for metal science study. At the cross polished sections the defect cavity have several branches, the cavity walls are twisting, around the cavity branches and next to them, aggregation of small globular oxides and massive decarburization were observed. The defects of rolled products surface were classified as rolled-out cracks (cross orientation). The cracks depth in the section under study was 0.6–3.5 mm. Based on the results of the study the surface defects of rolled products were properly classified and reasons of their arising revealed, that will allow avoiding their formation in the future. Based on the proper classification and avoiding of the surface defects reasons, the rolled products rejects by surface defects will be considerably decreased.

scholarly journals Influence of unevened grains of metal on the mechanical properties of seamless hot – rolled pipes.

2020 ◽  
pp. 31-33
Author(s):  
I. A. Kovaleva ◽  
N. A. Khodosovskaya ◽  
M. V. Oborov
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Physical And Mechanical Properties ◽  
World Market ◽  
Grain Structure ◽  
Pressure Drops ◽  
Impact Performance ◽  
Hot Rolled ◽  
The Impact

Seamless hot – rolled pipes are a popular metal product on the world market. During operation, pipelines are subjected to cyclic loads associated with temperature fluctuations, vibrations near compressor stations, and pressure drops in the transformed medium. One of the ways to ensure high performance properties is to manage the quality of pipe metal, including that laid in the process of metallurgical production. All the basic physical and mechanical properties of metal materials are structurally sensitive and significantly depend on both the grain size and the degree of uniformity of the grain structure, that is, on the different grain sizes. For metallographic research, samples of pipes with the size of 70,0×12,5 mm of S460NH steel were selected with satisfactory (#1) and unsatisfactory (#2) results of the impact. It was found that the inhomogeneous (multi – grained) microstructure in sample #2 was the reason for obtaining unsatisfactory results of the impact. As a result, it was found that one of the most important characteristics that can guarantee stable and satisfactory results of mechanical characteristics, in particular the impact performance, is a homogeneous grain structure.

scholarly journals Research of defects of hot-rolled steel having rolling nature of formation of the rolling shop no. 1 of rolling mill 850 at OJSC «BSW – Management Company of Holding «BMC»

2019 ◽  
pp. 60-68
Author(s):  
I. A. Kovaleva ◽  
Yu. A. Potapenko
Keyword(s):  
Rolling Mill ◽  
Western Europe ◽  
Great Influence ◽  
Rolled Steel ◽  
Management Company ◽  
Defects Analysis ◽  
Quality Of Products ◽  
Hot Rolled ◽  
Hot Rolled Steel

Rolling is the final stage of the metallurgical cycle and has a great influence on the quantity and quality of products, as well as on various technological and economic indicators of the plant.The OJSC « BSW – Management Company of Holding «BMC» is working on the development and supply of hot-rolled round products for the automotive industry in Western Europe.The increasing requirements for the quality of the surface of hot-rolled steel are a powerful incentive to improve the technology of its production, which is impossible without the use of modern methods of control and proper identification of detected defects.The article presents the results of the study of defects of hot-rolled products of rolling mill № 1 850, having the rolling nature of formation.Metallographic study was conducted on the basis of: visual inspection of defects, in some cases with the preparation of a template for the study of macrostructure and location of defects; analysis of images of the microstructure of the cross section of the sample in the area of defects. With the help of characteristic external and microstructural features of defects, special etching in reagents, the causes of their formation were established, and recommendations for their minimization or complete elimination were proposed.

Interrelation of CCM (Steel Billet Continuous Casting Machine) Tube Steel Casting Parameters and Hot-Rolled Plate Quality

2021 ◽  
Vol 316 ◽  
pp. 479-483
Author(s):  
A.M. Stolyarov ◽  
Ye.A. Buneyeva ◽  
M.V. Potapova
Keyword(s):  
Continuous Casting Machine ◽  
Casting Machine ◽  
Intermediate Ladle ◽  
Rolled Plate ◽  
Tube Steel ◽  
Liquidus Point ◽  
Metallic Inclusions ◽  
Hot Rolled ◽  
Rolled Plates

The quality of the hot-rolled plate up to 36 mm thick was estimated by the percentage of rolled products, sorted due to the presence of a surface defect "Non-metallic inclusions", and internal defects, detected by ultrasonic plate control. The analysis of the data on the total sorting of hot-rolled plates demonstrated that the amount of sorting differs significantly on the melting from which each series of tubular metal casting commenced, compared to all the other melting in the series. The sorting of the sheets rolled from the metal of the first in a series of melting proved to be 1.9 times higher than that of the metal of all other melts. The main reason (in 68% of cases) of sorting is the presence of non-metallic inclusions on the surface of the plates. The effect of sorting of hot-rolled plates on non-metallic inclusions of various parameters has been studied: the duration of the intermediate ladle-heating; the length of time from the end of the heating of the intermediate ladle, prior to the beginning of the casting; lining temperatures of the intermediate ladle before the beginning of casting; duration of filling the intermediate ladle; the filling rate of the intermediate ladle with metal; mass of metal in the intermediate ladle before the beginning of casting into the crystallizer; chemical composition of metal; overheating of the metal over the liquidus point at the beginning, middle and end of the casting. On the sorting of flat products for non-metallic inclusions, of all the parameters considered, a statistically significant effect is due only to the overheating of the metal above the liquidus point, which varies in the range from 19 to 35 ° C. In order to obtain an acceptable quality of both the surface of slabs and the surface of hot-rolled plates for non-metallic inclusions, the first in a series of melts recommends overheating of the metal in the intermediate ladle above the liquidus temperature of 30-35 ° C.

Increasing the Durability of Roller-electrodes in Electrocontact Surfacing of Parts of Mobile Agricultural and Transport Equipment

2020 ◽  
pp. 133-139
Author(s):  
Viktor Dubovyk ◽  
◽  
Yurii Nevdakha ◽  
Viktor Pukalov ◽  
Vlvdyslav Chernov ◽  
...  
Keyword(s):  
Welded Joint ◽  
Negative Impact ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Transport Equipment ◽  
Repair Costs ◽  
Negative Effect ◽  
Hot Rolled ◽  
Traction Power

During the operation of mobile agricultural and motor vehicles, their connections and parts are activated. This leads to a decrease in traction power, operating speed, quality and productivity when performing technological operations. Repair costs are constantly rising, so the question of finding inexpensive technologies for the restoration of worn parts is relevant. Such technologies include electro-contact surfacing. One of the reasons that constrains the widespread use of the method of electrocontact surfacing is the low stability of the electrode roller. Currently, little research has been conducted to study the wear of the electrode rollers and increase their wear resistance. The research on search of ways of increase of durability of rollers-electrodes at electrocontact surfacing is carried out. The operating conditions of the electrode rollers and their operation, the strength of the welded joint when using a tool with different degrees of operation were considered. The operation of the roller-electrode during electro-contact surfacing has a negative effect on the strength of the welded joint of the metal coating with the base due to the reduction of deformation of the filler wire. The results of tests for operation show that a significant reduction in the quality of the welded joint occurs when using electrodes made of hot-rolled copper after 1.5...2 hours of operation. It is not possible to fully compensate for the negative impact of the electrode operation on the quality of the welded joint by adjusting the technological modes of surfacing. This indicates the need for 2 - 3 times the replacement of such tools, after grooving their working surfaces on a lathe. Developed recommendations for the choice of sizes of rollers-electrodes used in electro-contact surfacing of parts of mobile agricultural and transport equipment.

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