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2022, Vol.32 Num.6
Online: 2022-06-15
Summarization of Technology
Monographic Study
Production Technology
Metallurgy Talent
Metallurgical Science and Technology Award
Summarization of Technology
2
SONG Zhi-gang, FENG Han, WU Xiao-han, HE Jian-guo, LI Guo-ping, ZHANG Yan-rui
Development and research progress of duplex stainless steel in China
Combined with the development characteristics of duplex stainless steel in China, its development is expounded from the aspects of technological progress, output increase, application expansion and development trend. Following the international development trend, duplex stainless steel in China has experienced the development process from the first generation to the third generation and economic duplex stainless steel, and the development and application of super duplex stainless steel are also being actively explored. Although the research and development of duplex stainless steel in China started late, the developing direction of N-alloying duplex stainless steel was established in the early stage, which was synchronous with international duplex stainless steel. Chinese duplex stainless steel practitioners have consistently focused on process improvement and technological progress. The research and progress in various aspects such as microstructure control and performance enhancement, thermoplasticity, precipitated phase, especially the progress in microstructure and performance balance regulation, low temperature impact toughness research and performance enhancement of duplex stainless steel in recent years, will strongly support the growth of production and expansion of applications for duplex stainless steel in China. With the development of technology and market situation, the production of duplex stainless steel in China has increased rapidly from 2015 to 2021, of which the production in 2021 reached 240 600 t. It could be predicted that duplex stainless steel in China would be further developed in many aspects such as quality, production, variety and application.
2022 Vol. 32 (6): 2-14 [
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15
LIU Shi-feng, WEI Gang, WANG Yan, ZHOU Jian, MA Dang-shen, CHI Hong-xiao
Research progress on additive manufacturing of 17-4PH martensitic stainless steels
17-4PH martensitic stainless steel possesses high strength, high toughness, good corrosion resistance and other excellent properties, and is widely used in aerospace, nuclear and civil industries. Additive manufacturing technology, using the preparation method of discrete accumulation, can accomplish the manufacturing of complex shaped parts to satisfy the requirements of equipment iteration. Research results of additive manufacturing 17-4PH at domestic and foreign is summarized, factors affecting the density of additive manufacturing 17-4PH specimens are introduced under the characteristics of additive manufacturing with small molten pool, rapid melting and complex thermal history. Meanwhile, the phase composition, microstructure and mechanical properties of additive manufacturing are reviewed. The influence of post-treatment on mechanical properties is briefly elaborated, and finally the development of additive manufacturing 17-4PH is prospected.
2022 Vol. 32 (6): 15-25 [
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ZHAO Jin-long, LIN Hong-liang, YANG Chun-guang, YANG Ke
Application and research status of antibacterial Cu-bearing stainless steel
Antibacterial Cu-bearing stainless steel (SS) is a kind of novel metal material with integrated structure and function. At present, it has stable industrial scale production capacity. A variety of antibacterial Cu-bearing SS have been developed for daily life, medical field and marine engineering equipment, which are used to deal with the microbial contamination problems in the corresponding filed. In order to explore the development direction of antibacterial Cu-bearing SS, the research progress and application status in many fields of the key properties for antibacterial Cu-bearing SS are reviewed synthetically. Furthermore, the new problems and challenges brought by the times are analyzed.
2022 Vol. 32 (6): 26-41 [
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42
LIU Zhen-bao, LIANG Jian-xiong, YANG Zhe, WANG Xiao-hui, SUN Yong-qing, WANG Chang-jun, YANG Zhi-yong
Progress of application and research on high strength stainless steel
High strength stainless steels (HSSSs) play a vitally important role as a material candidate applied into advancing manufacturing industries, such as aeronautics and astronautics, maritime engineering, and petroleum engineering, due to the excellent service performance and mature production processes. The development and application history of HSSSs is systematically reviewed. The strengthening and toughening mechanisms of this steel grade as well as iron-based materials and the latest research results on the topic are also summarized. Besides, the primary factors exerting impact on the hydrogen trapping behavior and hydrogen embrittlement resistance of HSSSs are analyzed. Based on the current results, it is further proposed that the co-strengthening of multiple nano-scale secondary phases is a promising pathway to break through the limit of strength-toughness synergy. Both the mechanical and chemical stability of reversed austenite can be enhanced by tuning the precipitation interaction between the precipitates and reversed austenite. Stable austenite phase acts as a dual “trap” of both cracks and diffusible hydrogen atoms, which effectively improves the resistance of cracking and hydrogen embrittlement. It is eventually suggested that special attention should be paid to the “artificial intelligent” alloy designing concepts, including materials genetic algorithm, artificial neural network, and machine learning, for the future research and development of HSSSs.
2022 Vol. 32 (6): 42-53 [
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LI Bing-bing, LANG Yu-ping, CHEN Hai-tao, QU Hua-peng, FENG Han-qiu, TIAN Zhi-ling
Development of super austenitic stainless steel
The increasing industrial demand promotes the research and development of super austenitic stainless steel, three stages of super austenitic stainless steel in order of development time is described. The first stage is the development of stainless steel mainly to solve the corrosion resistance in sulfuric acid medium environment. The second stage is the development of several super austenitic stainless steels with good corrosion resistance by adding about 0.2%N element and increasing the mass fraction of Mo element to about 6% on the basis of the steel developed in the first stage. In the third stage, based on 6%Mo containing steel, Cr, Mo and N contents are greatly improved, the mass fraction of Mo element is increased to about 7%, the mass fraction of N element is controlled at about 0.5%, and appropriate amount of Mn is added to develop super austenitic stainless steel with excellent corrosion resistance. Two important technologies in the research and development of super austenitic stainless steel are described, e.g. secondary refining and nitrogen alloying, and the future development and application of super austenitic stainless steel are prospected.
2022 Vol. 32 (6): 54-60 [
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Monographic Study
61
CHEN Qi-wei, BAO Han-sheng, YANG Gang, WU Ming-hua, CAI Long, YANG Li-xia
Analysis of Nb segregation in continuous casting TP347H billet
Segregation of Nb is found in the TP347H billet produced by continuous casting process, inner wall cracking in cross rolling perforation is generated in the pipe after hot continuous rolling when the Nb segregation is serious, leading to the reduction of yield and low comprehensive performance of steel tube. In view of segregation phenomenon, the precipitation behavior of niobium containing precipitates was studied by means of thermodynamic calculation and experiment, the main factors affecting Nb segregation in continuous casting billet and the characteristics of primary MX phase (niobium carbonitride) precipitations were analyzed. The results show that composition optimization of TP347H steel produced by continuous casting process should focus on the content of C and Nb elements. And the segregation phenomenon of continuous casting TP347H billet exists in the central area of the billet, which leads to the difference in morphology and size of the primary MX phase precipitations between edge and central area of billet.
2022 Vol. 32 (6): 61-70 [
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71
MA Shuai, LI Yang, JIANG Zhou-hua, SUN Meng, CHEN Chang-yong, LIU Hang
Effect of Ce on inclusion evolution for 440C stainless bearing steel
In order to explore the modification effect of rare earth Ce on the inclusions in 440C stainless bearing steel, a laboratory MoSi
2
resistance furnace was used to treat 440C stainless bearing steel with rare earth Ce, and the effects of Ce addition on deoxidation and inclusion evolution of 440C stainless bearing steel were systematically analyzed by OM and SEM. The results show that with the increase of Ce addition, the yield gradually increases. The mass fraction of TO in steel is reduced from 0.002 5% to 0.001 2% by addition of Ce. The inclusions in steel without Ce element are mainly Al
2
O
3
, MnS and magnesium aluminum spinel, while the inclusions are modified to Ce-Al-O-based inclusions by adding 0.011 5% Ce. When the amount of Ce added reaches 0.036 4%, the inclusions are completely modified to Ce-O-S inclusions. The size and area ratio of inclusions can be reduced by a moderate amount of Ce, but the size of inclusions will be increased due to excessive addition of Ce. Under the test conditions, when the mass fraction of Ce is 0.011 5%, the fine dispersion effect of inclusions in steel is the most obvious. This study can provide a reference for the application of Ce in high-carbon chromium stainless bearing steel.
2022 Vol. 32 (6): 71-78 [
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79
MA Ming-yu, ZHOU Na, GONG Jian, LÜ Bao-feng, NIU Tao, GUAN Jian-dong
Effect of Ce and W on pitting corrosion resistance of 444-type ferritic stainless steel
The effect of Ce and W addition on pitting corrosion resistance of ferritic stainless steel in the solution containing Cl
-
was studied by electrochemical and gravimetric tests. The critical pitting temperature (CPT) of ferritic stainless steel with different Ce and W contents was measured by potentiostatic polarization method. The results show that addition of both Ce and W can inhibit the corrosion dissolution of ferritic stainless steel in FeCl
3
, and W element is enriched on corrosion pits bottom of stainless steels containing W. Both Ce and W increase the critical pitting temperature value of ferritic stainless steel in 5%NaCl solution. When the mass fraction of W element reaches 1%, the repassivation ability of corrosion pits can be significantly enhanced. The addition of Ce and W can increase the pitting potential of ferritic stainless steel, decrease the pitting current density, and improve the pitting resistance of the stainless steel. Ferritic stainless steels with different components show stable passivation in neutral solution containing chlorine, while the addition of Ce and W can improve the stability of passivation film and expand the range of passivation zone.
2022 Vol. 32 (6): 79-86 [
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87
LIU Xiao, TONG Wei-shuo, ZHAO Liang-qun, CHEN Lei, LIU Liu
Effect of Ce on corrosion behavior of duplex stainless steel in NaCl + HCl solution
In order to study corrosion resistance of duplex stainless steels in acid NaCl solution, corrosion resistance of UNS S31803 duplex stainless steel containing Ce in NaCl+HCl solution was tested by electrochemical anodic polarization and electrochemical impedance spectroscopy(EIS). The morphological characteristics after corrosion were observed by scanning electron microscope (SEM), the distribution characteristics of alloying elements and impurity elements were detected by electron probe micro-analyzer(EPMA), and the effect mechanism of Ce containing in the duplex stainless steels on the electrochemical corrosion behavior was analyzed. The results indicate that there is selective corrosion of two phases and local pitting corrosion in steel, and ferrite phase suffers more serious pitting corrosion. The results of anodic polarization and EIS are agreed very well, and the passivation range increases because of adding Ce. The corrosion resistance is improved due to the purification of molten steel, the reduction of S and P segregation at the phase boundary and the more uniform distribution of alloy elements such as Cr, Ni and Mo in the two phases by the addition of Ce.
2022 Vol. 32 (6): 87-93 [
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XIE Sheng-tao, SHAO Shu-dong, QI Hai-yan, WANG Jun-hai
Effect of rare earth elements on microstructure andproperties of 430 ferritic stainless steel
The conventional 430 ferritic stainless steel (FSS) was microalloyed with rare earth (RE) elements, and cold rolled and annealed (CA) sheets of 430RE FSS with higher qualities were finally developed. The effect of RE microalloying on the mechanical property, deep drawing ability, ridging resistance, microstructure and texture of 430 FSS were studied. By RE microalloying, most CaO·SiO
2
and Al
2
O
3
·CaO inclusions with relatively large size in 430 FSS are transformed into inclusions rich in RE elements with relatively small size and high distribution density in 430RE FSS. Compared with 430 FSS under similar hot rolling, cold rolling and annealing processes, the hot rolled (HR) band and CA sheets of 430RE both obtain lower strength and higher ductility, the texture evolution of 430RE during production displays stronger formation tendency of γ-fiber with high
r
-value, which conduces to higher deep drawing ability of 430RE CA sheet, and grain colonies with low
r
-value orientations assembling along rolling direction in 430RE CA sheet are reduced, which conduces to higher ridging resistance of 430RE CA sheet.
2022 Vol. 32 (6): 94-100 [
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101
FU Jin-zhu, WU Min, LI Guo-ping, LIU Chun-lai, DUAN Xiu-feng
Research and evaluation on microstructure and properties of ultra-purified ferritic stainless steel 425
425 steel is a resource-saving, ultra-purified ferritic stainless steel developed for the cold end of automobile exhaust system. Its chromium mass fraction is 15%, carbon and nitrogen are stabilized using Ti and Nb elements. The microstructure evolution and tensile properties of 425 steel after annealing at 880~1 000 ℃ were investigated by optical microscope, scanning electron microscope, electro-mechanical universal testing machines and electrochemical workstation, and the formability and corrosion resistance were compared with 409 and 439 steel. The results show that 425 steel has the best combination of microstructure and tensile properties after annealing at 960 ℃. The formability of 425 steel is equivalent to that of 439 and 409 steel, the pitting corrosion rate is slightly greater than that of 439 and significantly lower than that of 409 steel, and the pitting potential is between that of 409 and 439 steel. In general, 425 ultra-purified ferritic stainless steel has good plasticity, formability and corrosion resistance. It is an ideal material for cold end application of automobile exhaust system.
2022 Vol. 32 (6): 101-107 [
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108
JIANG Yi, SHI Xian-yun, JIANG Lai-zhu, KONG Qing-mao, JIANG Mei-xue, ZHENG Lan-zhen
Microstructure and properties of nitrogen contained low nickel austenitic stainless steel QN1701 for elevator
Nitrogen contained low nickel austenitic stainless steel QN1701(12Cr17Mn7Ni2Cu2N)was designed by Thermo-Calc software to replace 443(019Cr21CuTi) ultra pure ferritic stainless steel for elevator. Microstructure and properties of QN1701 and 443 stainless steel were investigated by means of OM, SEM, Electrochemical workstation and other methods. It was shown that yield strength of QN1701 stainless steel was increased to more than 400 MPa and was 1.32 times of that of 443 stainless steel for nitrogen playing a role of grains refining and solution strengthening. The pitting potential of QN1701 stainless steel was 241 mV, which was lower than 289 mV of 443 stainless steel, but its pitting rate was 9.10 g/(m
2
·h), which was lower than 14.58 g/(m
2
·h) of 443 stainless steel. The corrosion resistance of QN1701 stainless steel was significantly better than that of 443 stainless steel in the accelerated corrosion tests with environment of 10%NaCl neutral salt spray and cyclic exposure of wet and dry salt spray under the condition of grinding and wire drawing surface for elevator plate. The analysis found that (Nb,Ti) (C,N) precipitations generated by adding a certain amount of Nb and Ti to 443 stainless steel after grinding and wire drawing process, exposed to the surface or left a small pit after being dragged, which led its corrosion resistance to be reduced. In conclusion, QN1701 stainless steel has the characteristics of higher strength, elongation and better corrosion resistance on wire drawing surface, which is of great value for the light-weight design and longer service life of elevator.
2022 Vol. 32 (6): 108-116 [
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117
ZHAO Lei, YAN Hai-tao, MA Deng-de, SHEN Peng, LI Jie, LIANG Cui-feng
Microstructure and properties of new stainless steel for corrosion resistant heating pipe
Stainless steel materials for electric water heater mainly include 310S、840 and other materials. During the process of using, the electric heating pipe is easy to scale, resulting in corrosion failure of heating pipe. In order to solve this problem, according to the service environment of heating pipe, Mo element was added on the basis of 310S composition system, other alloy composition systems were also optimized and adjusted, and a new stainless steel material for corrosion-resistant heating pipe was developed. The microstructure, mechanical properties and corrosion properties of a new type heating tube stainless steel in hot rolling solution pickling state were studied and compared with 310S steel. The change law of alloy structure with temperature under equilibrium condition was analyzed by Thermo-Calc thermodynamic software. It is shown that the σ phase precipitation begin at about 900 ℃, but the number is small. Under the same rolling procedure and heat treatment procedure as 310S, the average values of tensile strength (
R
m
), yield strength (
R
p0.2) and elongation of hot-rolled solid solution pickling state of the new material are 611 MPa, 286 MPa, 52.8%, respectively. The overall strength is slightly higher than 310S, but the difference is small, and the elongation is slightly lower than 310S. The grain size of the new material is grade 5.5 and grade 7 in some areas. The grain size is slightly bigger than 310S, and there is little difference in whole. The average corrosion rates of new materials and 310S are 0.49 g/(m
2
·h) and 1.37 g/(m
2
·h) respectively. It can be seen that the pitting corrosion resistance of new materials is significantly better than 310S steel.
2022 Vol. 32 (6): 117-122 [
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123
YANG Chen, GAO Ya-long, ZHOU Ji-hua, SHEN Hong-ying, SHI Hong-ming, ZHANG Jie-wei
Analysis on torsional properties of 316 austenitic stainless steel wire for nuclear power
Aiming at the problems of non-uniform unidirectional torsional properties and abnormal fracture in the development of austenitic stainless steel wire for nuclear power, the metallographic structure, unidirectional torsional fracture and surface morphology near the fracture were studied by means of optical microscope (OM) and scanning electron microscope (SEM). It is found that the main reasons for non-uniform of unidirectional torsional properties and abnormal fracture are the poor surface quality of steel wire and overburning at the welded joint of steel bar. By changing the drawing die material from tungsten steel to polycrystalline and the lubricant from lubricating powder to water-soluble grease, the surface quality of steel wire is improved. By reducing the heat input during welding at the welded joint properly, the problem of abnormal fracture in unidirectional torsion test is solved. After improvement, the unidirectional torsion turns tends to be uniform, and the maximum number of torsion turns can be up to 169, which is much higher than the technical requirements.
2022 Vol. 32 (6): 123-128 [
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129
ZHONG Qiang, QIAN Jiong, WU Jing-na, ZHAO Xin-hua, MA Rong-li, LIU Zheng-dong
Effect of surface treatment on pitting corrosion resistance of 316L stainless steel for offshore engineering
316L stainless steel is a commonly used corrosion-resistant alloy material, however, it is prone to pitting corrosion in the marine and atmospheric service environment. The pitting corrosion resistance of 316L tubes after various surface treatments (bright annealing, polishing and pickling passivation) was evaluated by pitting rate, critical pitting temperature, pitting potential and polarization curve test. The results show that different surface treatments have no significant influence on the critical pitting temperature, but the pitting rate and pitting potential will differ. Polishing and pickling passivation can effectively improve the pitting corrosion resistance of 316L stainless steels, of which the pickling passivation state has the best pitting resistance, so it is recommended that the 316L stainless steel products for offshore engineering should be pickling passivation treatment before use.
2022 Vol. 32 (6): 129-133 [
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134
ZHANG Jun, ZHANG Xiu-li, LI Zao-yu, YANG E
Effect of sulfide morphology on mechanical properties of free-cutting stainless steel 1Cr17MoS
Sulfide morphology in free-cutting stainless steels 1Cr17MoS is shown different with different control techniques in steelmaking practice. For 1Cr17MoS steels with traditional steelmaking practice and forging process, sulfides presented thin and long stringers with the length of 50-80 μm and aspect ratio of 5-12,the sizes of sulfides were generally between 1 μm and 5 μm and most sulfides were less than 3 μm. However, for 1Cr17MoS steels with the addition of microalloying elements in steelmaking practice and forging process, spindle and globular sulfides were formed with the length of 10-30 μm and aspect ratio of 2-5, sizes of sulfide were generally between 3 μm and 20 μm and most sulfides were between 10 μm and 20 μm. The longitudinal and transverse tensile tests of 1Cr17MoS steel with different sulfide morphology were carried out. It is testified that fractures in 1Cr17MoS steels are dimple fractures in longitudinal tensile test at both conditions, the quantity and size of dimples are influenced by the quantity and thickness of sulfides, while the morphology of dimples have no obvious effect on mechanical properties of steels. The transverse tensile fractures of 1Cr17MoS steels are mainly quasi-cleavage fractures, and also have partial dimple fractures at both conditions. In traditional steelmaking practice with no sulfide morphology treatment, sulfide stringers break the continuities of matrix for test steel, which accelerate the brittle rupture of transverse tensile fractures. However, with sulfide morphology treatment in steelmaking practice, sulfides in spindle and globular shapes occur as dimples in fracture, which lead to better transverse tensile properties due to the remained plastic properties.
2022 Vol. 32 (6): 134-138 [
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139
WANG Wei, ZHANG Zhuang, ZHANG Li-ping, DUAN Cai-feng, SHANG Guang-hao, ZHANG Jia-quan
Characteristics and formation mechanism of surface peeling defects on rolled plates of a nickel-saving austenitic stainless steel
The frequently observed surface peeling defects on the hot and cold-rolled plate of a kind of nickel-saving austenitic stainless steel have an extremely influence on the qualification rate of the final products. The macroscopic morphology, microstructure and element composition of the peeling defects were observed and analyzed by means of metallographic microscope, scanning electron microscope and electron backscattered diffraction, respectively, to explore the cause of peeling defects. The results show that there are obviously embedded Cr and Mn metal oxides on the surface and longitudinal section of peeling defects of the hot-rolled plate, and their chemical composition is highly consistent with their common iron oxide scales. In addition, the residual ferrite structure is found in the longitudinal section of the peeling defect of the hot-rolled plate by EBSD scanning. The thermoplastic difference between ferrite and the matrix austenite phase during rolling might lead to local micro-cracks and oxide embedding, which grows into the oxidative peeling defect frequently observed on the hot-rolled plate. The peeling defect of cold-rolled plate comes from the hidden defect of hot-rolled plate. The abnormal composition of the peeling defect of the cold-rolled plate is basically consistent with the exogenous inclusion such as tundish covering flux and mold protective flux, which is involved into the liquid steel during the casting process and could mostly be exposed during the final cold rolling process. The latter could be defined as inclusions induced peeling defects, which appears as linear peeling and spalling peeling. Through the improvement of continuous casting tundish and submerged nozzle process, the proportion of peeling defects on the surface of this kind of stainless steel rolled sheets could be effectively reduced.
2022 Vol. 32 (6): 139-146 [
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Production Technology
147
FENG Han-qiu, LANG Yu-ping, QU Hua-peng, CHEN Hai-tao
Cracking analysis and improved measures of intermediate crack in hot rolled medium plate of niobium-bearing stainless steel
Aiming at the problems of intermediate crack delamination and unqualified mechanical properties in hot rolled medium plate of niobium-bearing stainless steel, the causes of intermediate crack delamination and unqualified mechanical properties were studied by means of metallographic observation, scanning electron microscope, phase analysis and mechanical property detection. The results show that σ phase and Z phase (CrNbN) which formed by the serious segregation of Mo and Nb are the main causes of the intermediate crack delamination and unqualified mechanical properties in hot rolled medium plate. By reducing Nb content, optimizing heat treatment system, reducing liquid steel superheat, determining reasonable cooling system and adding electromagnetic stirring process, the occurrence of intermediate crack can be effectively reduced and low temperature impact toughness can be improved.
2022 Vol. 32 (6): 147-154 [
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155
ZHAO Bin, WU Wei, WU Wei, ZHANG Na, CHU Xiao-rui
Dephosphorization process of hot metal by powder spraying and oxygen blow for stainless steel production
In order to meet the requirements of pre-dephosphorization in the production of ultra-low phosphorus steel, the dephosphorization process of stainless steel hot metal was introduced. The industrial experiment of lime powder spraying+oxygen blowing in 45 t ladle was carried out. The results show that after the expected effect is achieved (
w
([Si])≤0.1%) in the hot metal desilication period, the average dephosphorization rate can be greater than 88% in the hot metal dephosphorization period. The calculation formulas of dephosphorization rate and phosphorus ratio in desilication period and dephosphorization period were regressed respectively. By adding fluorite, a better dephosphorization effect of hot metal could be obtained. With the increase of hot metal silicon content, hot metal temperature, oxygen consumption per ton of steel, lime consumption and slag basicity, the dephosphorization rate of hot metal increases significantly. The increase of
w
((TFe)) in slag has no significant effect on the dephosphorization rate of hot metal. It is considered that the current stainless steel hot metal dephosphorization method using lime powder spraying+oxygen blowing smelting is a very effective method for stainless steel hot metal dephosphorization.
2022 Vol. 32 (6): 155-162 [
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163
TAN Qing-feng, CHEN De-li, YAN Zhan-dong, JIA Hong-shuai, HAN Zhi-yuan, WANG Yu-hui
Practice on EAF+LF+VOD/VHD smelting process of super duplex stainless steel
The smelting process of super duplex stainless steel in Fugang was introduced. The production practices of vacuum oxygen blowing in VOD furnace, nitrogen blowing at bottom, secondary slagging and line feeding were carried out. The results show that low carbon content and accurate nitrogen content control are realized by setting reasonable oxygen and nitrogen blowing technology. In the reduction process, the appropriate slag basicity is adjusted, the molten steel is fed, the desulfurization and deoxidation are strengthened, the inclusion morphology is modified, and the precise chemical composition and good purity control of molten steel are ensured, which create favorable conditions for hot processing.
2022 Vol. 32 (6): 163-167 [
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168
CHEN Lian-yun, ZHOU Min, CHEN Ying-juan, TAN Guang-yao, MA Jin-jiang
Application of modular finishing rolling technology in high-speed wire production line of stainless steel
Numerical analysis, finite element analysis and laboratory experiments were used to study the influencing factors and wide spread model of deformation in high-speed wire finishing rolling, the coupling stiffness and stiffness model of modular finishing mill, and the control strategy of steel biting speed drop during high-speed rolling. The upgrade was made in view of long-term problems for poor stability and large fluctuation of product dimensional accuracy caused by inaccurate receiving and discharging profile in the finishing mill of stainless steel high-speed wire production line, the application of modular finishing rolling technology in stainless steel high-speed wire was realized through high adaptability pass system, high stiffness modular high-speed mill and high-speed rolling speed drop control technology. Aiming at the problem that the wire was easy to be scratched at climbing section, the sliding friction climbing guide groove was optimized into the rolling friction three roll guide groove, and the looper before finishing mill was changed into vertical looper. The production results show that the operation of modular finishing mill is stable, the vibration value of bevel gear box is less than 2.8 mm/s, the dimensional accuracy of outlet profile for finishing mill is more than 20% higher than that before the transformation, and the dimensional accuracy and surface quality of the final product are significantly improved.
2022 Vol. 32 (6): 168-174 [
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Metallurgy Talent
175
2022 Vol. 32 (6): 175-175 [
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176
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Metallurgical Science and Technology Award
177
2022 Vol. 32 (6): 177-177 [
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178
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