Laboratory Controlled Rolling of Microalloyed Steel for Production of Seamless Tubes

2016 ◽  
Vol 258 ◽  
pp. 611-614 ◽  
Author(s):  
Petr Kawulok ◽  
Radek Jurča ◽  
Ivo Schindler ◽  
Stanislav Rusz ◽  
Rostislav Turoň ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Hsla Steel ◽  
Tensile Tests ◽  
Strength Properties ◽  
Controlled Rolling ◽  
Rolling Temperature ◽  
Plastic Properties ◽  
Finish Rolling Temperature ◽  
Finish Rolling ◽  
Rolling Temperatures

Using the laboratory rolling mill with smooth rolls, piercing, as well as rolling in a pilger mill of the seamless tubes with diameter 273 mm from the HSLA steel microalloyed with vanadium steel was simulated. Influence of the wall thickness (6.3 – 40 mm) and finish rolling temperature on the final structural and mechanical properties was investigated. Necessary temperatures of the phase transformations in the course of cooling were determined by dilatometric tests. Based on the dilatometry results, finish rolling temperatures were reduced. Lower rolling temperatures yielded in a relative grain refinement. Effect of the finish rolling temperature did not have any marked impact on the tensile tests results. Strength properties decreased only slightly with the increasing wall thickness and the plastic properties were not influenced significantly by this parameter. The positive effect of the reduced finishing temperature appeared markedly in the results of impact tests performed at room temperature only. Notch toughness was increased by approx. 25 % in the case of the wall thickness of not less than 20 mm.

Microstructure Influenced by Controlled Rolling, Cooling and Thermal Processing of Seamless Tubes Made of Steel 25CrMo4

2020 ◽  
Vol 405 ◽  
pp. 121-126
Author(s):  
Petr Kawulok ◽  
Ivo Schindler ◽  
Stanislav Rusz ◽  
Rostislav Kawulok ◽  
Petr Opěla ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Controlled Rolling ◽  
Rolling Temperature ◽  
Compression Tests ◽  
Structural Variations ◽  
Finish Rolling Temperature ◽  
Finish Rolling ◽  
Physical Simulations ◽  
Plain Strain ◽  
Quenching And Tempering

By use of physical simulations, it was studied the influence of finish rolling temperature (from 820 °C to 970 °C) on the microstructural and mechanical properties of seamless tubes with a different wall thickness (from 6.3 to 40 mm) – in the state after rolling as well as after quenching and tempering. In laboratory conditions, by use of the Simulator HDS-20, the bloom piercing and rolling of the seamless tubes from 25CrMo4 low-alloy steel in a pilger mill were in a simplified way simulated. The wall thickness of the tube influenced the total deformation of specimens at anisothermal multi-pass plain-strain compression tests as well as the final cooling rate. The quenching and tempering of the deformed specimens was subsequently performed with use of the electric resistance furnaces. The finish rolling temperature had only insignificant effect on the resulting properties. Markedly lower hardness was obtained only after the simulation of tube production with the wall thickness of 40 mm contrary to the wall thickness of 6.3 and 20 mm. Structural variations of the specimens after rolling simulations were more or less overlapped by the subsequent quenching from the temperature of 850 °C and tempering at the temperature of 680 °C.

Thermal-Mechanical Simulation of the Controlled Rolling and Cooling Process by Orthogonal Design for Pipeline Steel

2012 ◽  
Vol 557-559 ◽  
pp. 2355-2360 ◽  
Author(s):  
Min Jiang ◽  
Li Na Chen ◽  
Wei Pang ◽  
Chong He Li ◽  
Xiong Gang Lu
Keyword(s):  
Cooling Rate ◽  
Heating Temperature ◽  
Pipeline Steel ◽  
Great Influence ◽  
Control Process ◽  
Controlled Rolling ◽  
Rolling Temperature ◽  
Cooling Temperature ◽  
Finish Rolling Temperature ◽  
Finish Rolling

A novel pipeline steel was prepared by the vacuum inducting technology, using Gleeble-3500 hot simulator, its parameters of thermo-mechanical control process (TMCP), such as heating temperature, finish rolling temperature, finish cooling temperature and cooling rate, have been studied by the orthogonal experiment with four factors and three levels. Through the orthogonal theoretical analysis, it is found that the sequence of the effect of parameters on the mechanical property is: Cooling rate > Heating temperature > Finish cooling temperature > Finish rolling temperature, the cooling rate is the most important factor affecting the inspection target and possesses a great influence on the hardness of the pipeline steel.

Production of Ultrafine Grained API X70 Steel with Controlled Rolling

2013 ◽  
Vol 829 ◽  
pp. 884-888
Author(s):  
Reza Abdideh ◽  
Mohammad Hizombor ◽  
Reza Mohammadian Rad ◽  
Iman Mohammad Zadeh
Keyword(s):  
Thermomechanical Treatment ◽  
High Strength ◽  
Cost Effective ◽  
Mechanical Tests ◽  
Controlled Rolling ◽  
Rolling Temperature ◽  
Microalloyed Steels ◽  
Finish Rolling Temperature ◽  
Finish Rolling ◽  
Ultrafine Grained

Development of industries in recent years reveals the essential need to the microalloyed steels with high strength and good ductility. Refinement of Ferrite grains by thermomechanical Treatment is the only lower cost effective method to improve strength and toughness spontaneously in this type of steels. API X70 steel belongs to high strength microalloyed steel group. The manufacturing process of this steel is controlled rolling which is a kind of thermomechanical treatment and it is considered as a grain refining method. In this research, three specimens of API X70 steel were experimentally rolled in order to achieve ultrafine grained microstructure. Rolling operations are designed in such a way that the rolling of these specimens finished at 846, 823 and 800°C. Results of the experiments were analyzed by mechanical tests and microstructures observations. The microstructure observations show that decreasing of finish rolling temperature causes decrease in Ferrite grain size. Results also show that rolling of API X70 steel in the vicinity of Ar3temperature and high strain rates lead to ultrafine Ferrite grains in microstructure. This is due to the transformation of work hardened austenite to Ferrite. On the other side, Tensile and impact tests show that decreasing of finish rolling temperature causes increasing in yield and tensile strength and also improves the toughness.

Influence of Finish-Rolling Conditions on Microstructure and Mechanical Properties of Low-Alloy Mn-Ni-Cr-Mo Steel Grade

2011 ◽  
Vol 465 ◽  
pp. 386-389
Author(s):  
Petr Kawulok ◽  
Rostislav Kawulok ◽  
Ivo Schindler ◽  
Jaroslav Sojka ◽  
Martin Kraus ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical Simulation ◽  
Thermomechanical Processing ◽  
Tensile Tests ◽  
Ultimate Tensile Stress ◽  
Rolling Temperature ◽  
Air Cooling ◽  
Slow Cooling ◽  
Finish Rolling Temperature ◽  
Finish Rolling

A physical simulation of the thermomechanical processing of the Mn-Ni-Cr-Mo low-alloy steel was performed in the laboratory rolling mill Tandem in the Institute of Modelling and Control of Forming Processes at VŠB – Technical University of Ostrava. The task was to determine the influence of the finish rolling temperature on the structural and mechanical properties of the rolled products. After different modes of rolling and slow cooling in the furnace, the final structure of the tested samples was in all cases composed of ferrite, bainite and islands of martensite. The finish rolling temperature markedly influenced a part by volume of the individual phases as well as the structure homogeneity. The results of the tensile tests at room temperature indicated that the studied steel did not show any pronounced dependence of the yield stress on the finish rolling temperature in the investigated range of values (750 – 1000 °C). On the other hand, the closely corresponding dependences of the ultimate tensile stress and elongation exhibited a considerable and very complex course, which can be explained mainly by the martensite fraction originating during the last stage of the final air cooling from temperature 600 °C.

Reason Analysis and Solutions of Low Coiling Temperature at Tail of ZSAC1 Strip during U-Type Cooling

2014 ◽  
Vol 988 ◽  
pp. 290-295
Author(s):  
Zhi Min Zhang ◽  
Feng Qin Wang ◽  
Fei Li ◽  
Shu Zhi Wang ◽  
Xiao Jiang
Keyword(s):  
Rolling Speed ◽  
Rolling Temperature ◽  
Cooling Process ◽  
Coiling Temperature ◽  
Running Speed ◽  
Factors Affecting ◽  
Finish Rolling Temperature ◽  
Finish Rolling ◽  
Improve Accuracy ◽  
Main Factors

Coiling temperature, finish rolling temperature and running speed of ZSAC1 strip during U-type cooling and number of valves which had been turned on were analyzed in order to find out the reason of low coiling temperature at tail of ZSAC1 strip in U-type cooling process. Results of research showed that running speed of strip and finish rolling temperature were main factors affecting accuracy of coiling temperature. Coiling temperature decreased with the increase of running speed of strip. Coiling temperature fluctuation would occur at the same part of strip when finish rolling temperature increased or decreased. Holding rolling speed and rolling temperature of strip stably can improve accuracy of coiling temperature during downstream U-type cooling.

The Elaboration of Modernized Technology of Controlled Rolling Directed at the Formation of High Strengthening and Viscous Qualities in HSLA Steel

2019 ◽  
Vol 291 ◽  
pp. 13-19 ◽  
Author(s):  
Dmytro Laukhin ◽  
Oleksandr Beketov ◽  
Nataliia Rott ◽  
Anatoliy Schudro
Keyword(s):  
Production Efficiency ◽  
Thick Plate ◽  
Hsla Steel ◽  
Controlled Rolling ◽  
Temperature Deformation ◽  
Plate Rolling ◽  
Finish Rolling ◽  
Highly Dispersed ◽  
Strength And Plasticity ◽  
High Level

Under industrial conditions, it is common to avoid undesirable costly modernization of the existing equipment and increase the production efficiency. That is why as a basis of the solution to the scientific-applied problem, the authors took the idea of the adjustment of temperature-deformation regimes of metal-roll thick plate rolling for building constructions of the certain assignment in the way to initiate heterogeneous origination of ferrite on the polygonal boundaries of austenite as well as to form, before the finish rolling, as much as possible dispersed grain of hypoeutectoid ferrite. It must guarantee the formation of highly-dispersed final ferrite-perlite structure and the high level of strength and plasticity of the thick plate.

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