最新刊期
- 摘要：The microstructure， mechanical properties， wear resistance， and wear mechanism of NM550RE steel alloyed with 0.001 2% rare-earth w［Ce］ were systematically studied， and compared them with those of conventional NM550 steel. The results show that the conventional NM550 steel has an average original austenite grain size of 9.48 μm and a hardness of 553HBW. The addition of Ce refines the grain size， reducing the average austenite grain size to 7.55 μm and increasing the hardness to 579HBW. Meanwhile， the impact energy at -40 °C increases from 29.43 J to 34.63 J. The G65 abrasive wear test results show that the wear resistance of NM550RE steel is 1.11 times that of conventional NM550 steel. After rare-earth modification， the inclusions exhibit better compatibility with the matrix， while the steel possesses a fine grain size， higher hardness， and toughness. During wear， this helps hinder abrasive particles from penetrating into the matrix and prevents further development of ploughing grooves， thereby reducing their width and depth and resulting in superior wear resistance.关键词：Rare Earth Element Ce;Abrasive Wear;Wear Resistance;Wear Mechanism0|0|0更新时间：2026-05-14
- 摘要：To study the continuous cooling transformation behavior of 4330V low alloy high strength steel， experiments were conducted at different cooling rates 0.05-30 ℃/s using a quenching dilatometer. Optical microscopy， field emission scanning electron microscopy， and microhardness tester were used to detect and analyze the microstructure and Vickers hardness of the material after phase transformation at different cooling rates， and the continuous cooling transformation （CCT） curve of its supercooled austenite was plotted. The results showed that when the cooling rate was 0.05-0.15 ℃/s， the microstructure was mainly bainite + ferrite， belonging to the high-temperature and medium-temperature two-phase composite transformation zone， and the hardness values were all below 450 HV； when the cooling rate was 0.2-1 ℃/s， the microstructure was mainly bainite + martensite， belonging to the medium-temperature and low-temperature two-phase composite transformation zone， and the hardness was between 472-577HV； when the cooling rate was greater than or equal to 3 ℃/s， the microstructure was fully martensitic， belonging to the low-temperature martensitic transformation zone， and the hardness values were all above 593 HV.关键词：4330V Low Alloy High Strength Steel;Continuous Cooling Transformation;CCT curve;Microstructure;Hardness0|0|0更新时间：2026-05-14
- 摘要：The demand for large-scale high-end equipment has imposed more stringent requirements on the microstructure and segregation control of large ingots of nickel-based corrosion-resistant alloys. In this paper， for a 20-ton flat ingot of N08120 alloy， testing methods such as metallographic microscope， scanning electron microscope and electron probe micro-analysis were used to analyze the solidification structure and composition segregation tendency of the ingot， aiming to provide guidance for evaluating the solidification quality of large nickel-based alloy ingots in industrial production and formulating homogenization heat treatment processes. The results showed that the thicknesses of the fine-grained zone and the columnar grain zone of the ingot were approximately 5 mm and 116 mm， respectively， and there was no significant macroscopic compositional segregation along the thickness direction of the ingot. From the surface to the center of the ingot， there were significant changes in both the dendrite morphology and the secondary dendrite arm spacing （SDAS）. The dendrites in the surface layer were finer， the dendrite trunk length in the columnar grain zone increased and exhibited a certain degree of orientation， while the dendrites in the central equiaxed grain zone were coarse and lost their orientation. And the SDAS increased monotonically from 96 μm to 383 μm. Among the elements， Cr， Nb， and Mo in the interdendritic regions were positive segregation elements， C was negative segregation element， and Ni and Fe showed no obvious segregation tendency. The degree of segregation gradually increased from the surface layer to the center of the ingot， and the segregation of Nb leads to the precipitation of Nb-containing second phases.关键词：Nickel-based Alloy;Corrosion-resistant Alloy;Solidification Microstructure;Dendrite Morphology;Dendrite Segregation0|0|0更新时间：2026-05-14
- 摘要：To enhance the performance of Q355 steel for offshore wind power applications， it is necessary to further improve the cleanliness of the steel and reduce oxide inclusions. Based on the liquid bridge theory， this study found that the contact angle θ between inclusions and liquid steel and the critical aggregation spacing dC are positively correlated， and for 10 μm inclusions dC=0.022θ-2.33（μm）； moreover， the order of critical aggregation spacing dC is： CeO2>Ce2O3>CaO>MgO>Al2O3>CeAlO3. With thermodynamic calculations， when w［Al］=0.03% and w［Ce］＞0.000 5% in Q355 steel， the CeOₓ layer forms on the surface of Al2O3 inclusion. This increases the critical aggregation spacing， accelerates the aggregation and growth of inclusions， and speeds up their floating， thereby further improving the cleanliness of the molten steel. This study used Ce treatment experiments on 4 heats of 80-ton Q355 steel melts to verify the above analysis. The experimental results show that after Ce treatment， the w［T.O］ and the size of oxide inclusions are significantly reduced in the steel. When Ce adding is less than 0.1 kg/t， as Ce adding increasing， the total amount and size of oxide inclusions in the steel decreases， and the CeOx layer gradually thickens； when Ce adding increases to 0.15 kg/t， the density of oxide inclusions increases， that inhibiting inclusions floating， leading to an increase in the total amount of residual oxide inclusions in the steel.关键词：Liquid Bridge Theory;Cerium Treatment;Oxide Inclusion;Aggregation0|0|0更新时间：2026-05-14
- 摘要：36MnVS4 is a new generation of non-quenched-tempered（NQT） steel for medium-carbon micro-alloying connecting rods. Through V micro-alloying and nitrogen-controlled design， this steel achieve excellent comprehensive mechanical properties for the connecting rod.， So it is widely used in the manufacturing of passenger car engine connecting rods. However， in the production process of NQT connecting rods， there are often typical connecting rod defects such as uneven fracture or slag dropping，which seriously affects the assembly quality and performance of the connecting rod after fracture. Especially in the production process of 36MnVS4 connecting rods， this problem is more prominent. To this end， a systematic inspection， analysis and research on the fracture split defects of the 36MnVS4 connecting rod were carried out and the controlled forging and cooling process optimization was proposed. The optimal controlled forging and cooling process for the 36MnVS4 connecting rod has been established. The process parameters are implemented： rapid cooling above 660 ℃ to inhibit the precipitation of ferrite， and slow cooling below 660 ℃ to obtain coarse lamellar pearlite， ensuring that the connecting rod has qualified hardness indicators and has good expansion and breaking performance.关键词：Non-Quenched-Tempered Steel;Expansion and Breaking Defects;Controlled Forging and Cooling;Microalloying0|0|0更新时间：2026-05-14
- 摘要：Aiming at the problems of low inclusion removal efficiency and large temperature fluctuations caused by the uneven flow field of the 5-strand tundish in Huaigang Steel， the tundish dam wall was redesigned. Compared with the original scheme， the overall shape of the dam wall remained unchanged， and the main optimizations were made to the position， aperture and inclination angle of the diversion holes. CFD simulation and industrial tests confirmed that： by opening the diversion holes on the side，reducing the hole diameter，and increasing the inclination angle， the response time of the 3rd strand increased by 89.1 s， the peak time increased by 160.3 s， the average residence time increased by 179.9 s， and the dead zone volume was reduced by 19.7%. The optimized flow field parameters enhanced the inclusion removal capacity by expanding the floating path and residence time of inclusions； relying on a more uniform flow field distribution， the temperature difference between the 1 st and 3rd strands was reduced from 3 ℃-5 ℃ to 0 ℃-2 ℃， verifying the regulatory effect of flow field uniformity on heat transfer processes. In the production of difficult-to-cast steel grades such as bearing steel， the fluctuation amplitude of the stopper rod in the 3rd strand of the optimized scheme was significantly reduced， and the qualification rate of inclusion inspection for high-grade special steel rolled products was increased from 95% to 98%， which confirmed that the flow field optimization has industrial-level stability and significance for improving the cleanliness.关键词：Tundish;Dam Wall Optimization;Flow Field Simulation;RTD Curve;Inclusion0|0|0更新时间：2026-05-14
- 摘要：The evolution of primary carbides and the mechanism of microstructural stability in powder metallurgy AISI M3：2 steel during holding at different temperatures were systematically investigated. Scanning Electron Microscopy （SEM） was employed to characterize the microstructure and carbide precipitation characteristics of the material， and room temperature impact toughness tests were conducted to analyze the influence of microstructural evolution on mechanical properties. The research results indicate that during holding at temperatures of 1 100 ℃ and below， the M₆C-type （tungsten-rich） and MC-type （vanadium-rich） primary carbides in the steel exhibit good thermal stability. Their average size and volume fraction do not significantly change with increasing holding temperature and prolonging holding time. This phenomenon is primarily attributed to the initial microstructural homogeneity imparted to the material by the powder metallurgy preparation process， as well as the extremely high thermodynamic stability of the two carbides themselves. When the holding temperature is raised to 1 150 ℃ and the holding time is prolonged， the M₆C-type carbides with relatively low thermodynamic stability undergo substantial dissolution， leading to a sharp decrease in the overall volume fraction of carbides. Simultaneously， the undissolved residual M₆C-type carbides undergo significant coarsening and form discontinuous ring-like distribution characteristics at grain boundaries. The aforementioned microstructural evolution ultimately results in a significant reduction in the impact toughness of the material. Therefore， under prolonged holding conditions， 1 150 ℃ serves as the critical temperature for the microstructural stability of primary carbides in this type of high-alloy tool steel， providing crucial experimental data support for optimizing heat treatment process parameters and precisely controlling the hot working window.关键词：Powder Metallurgy Tool Steel;Carbide;Alloying Element;Austenitizing;Heat Treatment0|0|0更新时间：2026-05-14
- 摘要：Numerical simulation was carried out on the vacuum arc remelting （VAR） process of CrNiMoAlTi series precipitation-hardening stainless steel using the Meltflow-VAR software. The effects of different melting rates， helium pressures， and feeding processes on the molten pool morphology and the formation tendency of ingot black spot defects during the VAR process were calculated， and statistical analysis of inclusions was also performed. The results show that with the increase of melting rate， the molten pool morphology transforms from a shallow and flat "U" shape to a deeper "V" shape， and the mushy zone also expands with the rising melting rate. When the melting rate is 5.0 kg/min， the formation tendency of black spots in the core region is minimized， which is conducive to the floating of inclusions. The heat transfer efficiency of the helium layer increases with the increase of helium pressure. At a helium pressure of 300 Pa， the depth-diameter ratio of the molten pool reaches the minimum value， which is beneficial to heat transfer， reduces the risk of element segregation， and significantly improves the formation tendency of ingot black spots. The optimal setting of melting rate reduction rate in the feeding stage is 0.03 kg/min， which can increase the cooling rate of the feeding end and improve the formation tendency of ingot black spots. After the VAR process， the total number of TiN inclusions in the center of the ingot is less than that in the edge region of the ingot， and the total number of inclusions in the head of the ingot is more than that in the tail of the ingot. No inclusions larger than 25 μm are found in any part of the ingot， and the rating of various inclusions is ≤ 0.5.关键词：Precipitation-hardening Stainless Steel;Vacuum Arc Remelting;Numerical Simulation;Black Spot Defect;Inclusion0|0|0更新时间：2026-05-14
- 摘要：The service performance of GCr15SiMn bearing steel， a core material for critical components in high-end manufacturing， is highly sensitive to the mechanical properties of non-metallic inclusions. This study investigates CaO-SiO2-Al2O3 composite inclusions in GCr15SiMn steel and systematically examines the effect of the w（CaO）/w（SiO2） on their phase composition， silicate network structure， and micromechanical properties using X-ray diffraction， Raman spectroscopy， and nanoindentation. The results show that the inclusions initially form as amorphous glassy phases， and their crystallinity increases significantly with increasing w（CaO）/w（SiO2）. The phase composition evolves from an amorphous-dominated structure at low w（CaO）/w（SiO2） to stable crystalline phases such as CaSiO3， CaAl2Si2O8， and CaAl2O4 at high w（CaO）/w（SiO2）. With increasing w（CaO）/w（SiO2）， the silicate network undergoes pronounced depolymerization： the fraction of medium and high-polymerization units decreases， while that of low-polymerization units increases， accompanied by a continuous rise in non-bridging oxygen content. In terms of mechanical properties， the hardness of the inclusions generally decreases， whereas the elastic modulus increases steadily to 104.04 GPa. The fracture resistance parameter H3/E2 decreases from 0.071 GPa to 0.052 GPa， and the energy dissipation ratio Wp/Weincreases from 0.99 to 1.2. Inclusions with low w（CaO）/w（SiO2） possess a highly polymerized and dense network structure， endowing them with superior hardness and damage resistance， which contributes to enhanced overall hardness and damage tolerance of the GCr15SiMn bearing steel.关键词：GCr15SiMn Bearing Steel;Inclusions;Amorphous Phase;Silicate Network;Mechanical Property1|0|0更新时间：2026-05-12
- 摘要：The thermal compression deformation behavior and microstructure evolution of 2 200 MPa ultra-high-strength steel were experimentally investigated using a Thermomastor-Z thermal simulation machine. Stress-strain curves under different strain rates （0.01 s⁻¹， 1 s⁻¹， and 5 s⁻¹） and deformation temperatures （850–1 150 ℃） with an engineering strain of 60% were tested. By analyzing the stress-strain curves and conducting EBSD analysis on deformed samples， the effects of strain rates and temperatures on the deformation resistance and dynamic recrystallization process of 2 200 MPa ultra-high-strength steel were studied. The recrystallization activation energy of the experimental steel was determined through regression calculations. The results indicate， 1） Higher deformation temperatures and lower strain rates result in lower deformation resistance of 2 200 MPa ultra-high-strength steel； 2） Dynamic recrystallization is activated at the strain rate of 0.01 s⁻¹ when the temperature ≥900 ℃； at strain rates of 1 s⁻¹ and 5 s⁻¹， dynamic recrystallization is activated when the temperature ≥1 000 ℃. During hot working processing， higher strain rates should be applied at temperatures ≥1 000 ℃， while lower strain rates are recommended below 1 000 ℃； 3） The calculated recrystallization activation energy of 2200 MPa ultra-high-strength steel is 421.20 kJ/mol； 4） A constitutive model for the flow stress of 2 200 MPa ultra-high-strength steel was established.关键词：2 200 MPa-grade Ultra-High Strength Steel;Thermal Simulation;Hot Deformation Behavior;Dynamic Recrystallization;Recrystallization Activation Energy0|0|0更新时间：2026-05-12
- 摘要：To study the effects of different deoxidation methods on the evolution of inclusions and carbides in Cr12MoV steel， experimental steels smelted by three deoxidation processes （Al deoxidation， Al deoxidation combined with rare earth Ce composite deoxidation， and vacuum carbon deoxidation） were analyzed using scanning electron microscopy-energy dispersive spectroscopy （SEM-EDS） and the OTSInca automatic inclusion analysis system （Oxford Instruments）. The effect of the three deoxidation methods on the mass fractions of total oxygen （T.O） and total nitrogen （T.N）， the number， size， composition and morphology of inclusions， as well as the precipitation characteristics and distribution of carbides in Cr12MoV steel were explored. The results show that at 480 Pa， carbon exhibits stronger deoxidation and denitrification effects than Al and Ce. The mass fractions of T.O and T.N in the as-cast samples can be reduced to 0.000 7% and 0.002 7%， respectively. In the experimental steels produced by single Al deoxidation and vacuum carbon deoxidation， inclusions are dominated by fine Al₂O₃， with number densities of 165/mm² and 95/mm²， and average areas of 0.70 μm² and 0.66 μm²， respectively. After Al deoxidation combined with rare earth treatment， inclusions are mainly Ce₂O₂S， with an inclusion number density of 120/mm² and an average area of 2.0 μm². The participation of Ce in deoxidation reduces the total number of inclusions but increases their size. Carbides in both single Al deoxidation and vacuum carbon deoxidation samples exhibit a fish-bone morphology and distribute continuously along grain boundaries to form a network structure， with area fractions of 12.15% and 12.29%， respectively. In contrast， carbides in the Al deoxidation + Ce treatment sample are fine lamellar or granular， distributing discontinuously along grain boundaries in a chain-like or particulate form without forming a continuous network structure， and the carbide area fraction is 11.70%. Ce treatment can significantly refine carbides， break the continuous network structure and reduce the precipitation amount. Compared with Al deoxidation， vacuum carbon deoxidation has no obvious effect on the morphology and precipitation of carbides. This study suggests that， without considering time， replacing partial Al deoxidation with vacuum carbon deoxidation in the smelting of Cr12MoV steel is feasible. It can purify molten steel and optimize the properties of inclusions without affecting carbide precipitation. Al deoxidation combined with rare earth composite deoxidation has a significant effect on carbide control.关键词：Cr12MoV Die Steel;Inclusions;Carbides;Rare Earth Treatment;Vacuum Carbon Deoxidation1|0|0更新时间：2026-05-12
- 摘要：In order to meet the requirement of new-generation diesel engine injectors with higher injection pressure and higher working temperature， it is urgent to search for an alternative material to 18Cr2Ni2 steel for the needle-valve body. The carburized 18Cr2Ni2 steel， 2Cr13 steel and H13 steel were chosen to perform the friction and wear test in diesel against M2 high-speed steel. The coefficient of friction（COF）and wear resistance of three steels were compared， the wear mechanism was analyzed， and the possibility of replacing 18Cr2Ni2 steel with 2Cr13 steel or H13 steel as a new material of needle-valve body was explored. The results show that the average COF of 18Cr2Ni2， 2Cr13 and H13 against M2 high-speed steel in diesel is 0.111， 0.122， and 0.132， respectively. The wear rate of 2Cr13 steel and H13 steel is only 67 percent and 55 percent of 18Cr2Ni2 steel， respectively. The wear rate of 18Cr2Ni2 steel is the highest， which is mainly ascribed to the severest abrasive wear because of low hardness. Due to steep hardness gradient of carburized layer， the fatigue wear is exacerbated to some extent. Among the three steels， H13 steel exhibits the best wear resistance. It benefits from the combination of high hardness， suitable carburized layer depth and hardness gradient. Compared with H13 steel， 2Cr13 steel has lower hardness of both carburized layer and core， resulting in severer abrasive wear. Meanwhile， the shallow carburized layer of 2Cr13 steel makes the large-scale spalling easy， further aggravating the fatigue wear. From the viewpoint of wear resistance， H13 steel is a possible alternative material to 18Cr2Ni2 steel for the needle-valve body.关键词：Needle-valve Body;18Cr2Ni2 Steel;2Cr13 Steel;H13 Steel;Friction Coefficient;Wear Resistance0|0|0更新时间：2026-05-09
- 摘要：The high-temperature plastic deformation behavior of 2 200 MPa grade ultra-high strength steel was investigated using a Gleeble 3 800 thermal simulation test machine. The stress-strain curves of high-temperature tensile deformation at strain rates of 0.1 s-1 and 0.001 s-1 within the temperature range of 750 ℃-1 100 ℃ were obtained. Metallographic observation and EBSD analysis were conducted on the microstructure of the longitudinal section near the fracture surface， and scanning electron microscopy （SEM） was used to observe the fracture morphology. The high-temperature plasticity and dynamic recrystallization behaviors of 2 200 MPa grade ultra-high strength steel were investigated. The research results showed： 1） At both strain rates， the tensile strength of the test steel continuously decreased with increasing deformation temperature； 2） at the strain rate of 0.1 s-1， the reduction of area increased with increasing temperature during tensile deformation at 750 ℃-1 000 ℃， and decreased with increasing temperature when T> 1 000 ℃； at the strain rate of 0.001 s-1， the reduction of area showed two troughs， near 800 ℃ and 925 ℃， respectively； the reduction of area peaked at T=1 050 ℃， after which it decreased with increasing temperature； 3） based on the strength and reduction of area， the forgeability of the test steel can be calculated. At the strain rate of 0.1 s-1， the forging temperature range of the test steel was 880 ℃-1 100 ℃， and at the strain rate of 0.001 s-1， the forging temperature range was 850 ℃-1 100 ℃； 4） when the deformation temperature was ≥1 050 ℃， high-temperature molten dendrites appeared on the tensile fracture， and the initial forging temperature should be below 1 050 ℃； 5） when the strain rate was 0.001 s-1， the onset temperature of dynamic recrystallization was 750 ℃. When the strain rate was 0.1 s-1， the onset temperature of dynamic recrystallization was 880 ℃. When the deformation temperature was ≥ 900 ℃， the grain size at the strain rate of 0.1 s-1 was finer than that at a strain rate of 0.001 s-1， so the rapid forging process should be adopted in the early stage of forging； when the deformation temperature is less than 900 ℃， the dynamic recrystallization fraction is higher at a strain rate of 0.001 s-1. Therefore， a slow forging process should be adopted in the later stages of forging to obtain a uniform and fine forged microstructure. The optimal forging temperature range for 2 200 MPa grade ultra-high strength steel is between 880 ℃ and 1 050 ℃.关键词：2 200 MPa Grade Ultra-High Strength Steel;Thermal Simulation Tensile Test;High-Temperature Plasticity;Forgeability;Dynamic Recrystallization1|0|0更新时间：2026-05-09
- 摘要：In order to systematically study the effect of quenching and tempering temperature on the mechanical properties of 21Cr12MoV martensitic heat-resistant stainless steel， specimens of the steel were prepared using various heat treatment processes. Subsequently， tensile tests， hardness tests， impact tests， as well as metallographic and fracture surface analyses were conducted. The results show that the tensile and impact properties of the material are optimal when the quenching temperature is 1 050 ℃. The tensile strength is 973 MPa， and the impact energy is 37.6 J. As the tempering temperature increases， the strength and hardness of the material gradually decrease， while the impact toughness gradually increases. To achieve the optimal strength - toughness balance and the best overall performance of the product， the recommended heat treatment process consists of a quenching temperature of 1 050 ℃ and a tempering temperature of 680 ℃.关键词：21Cr12MoV Steel;Martensitic Heat-resistant Steel;Heat Treatment Process;Mechanical Properties5|0|0更新时间：2026-05-09
- 摘要：To improve the efficiency and reduce the energy consumption of an electromagnetic induction heater for steel ingot riser， an optimization method for the yoke is proposed. Using ANSYS multi-physics coupling simulation， the effects of the yoke on the magnetic field distribution， heating efficiency， and solidification of the steel ingot riser were analyzed. The results show that when the yoke is expanded to 130% of the coil area and its thickness is increased to 120 mm， magnetic flux leakage at the edges is suppressed under the same working conditions. This increases the magnetic flux density on the molten steel surface by approximately 80% and increases the Joule heating power by about 2.5 times. Meanwhile， the temperature distribution in the riser region becomes more uniform， solidification of the ingot is delayed， and the feeding channel duration at the riser line is extended by 18 min. Under the same excitation current of 692 A， this optimized design increases the heating power from 10.67 kW before optimization to 26.58 kW， achieving an efficient heating mode of "low current， high power" while reducing coil losses.关键词：Yoke;Induction Heating;Steel Ingot Riser;Heating Efficiency;Numerical Simulation7|55|0更新时间：2026-04-08
- 摘要：GCr15 is a typical representative of high-carbon chromium bearing steel， and surface decarburization can severely degrade its surface quality and service performance. This paper presents an experimental investigation and mechanism analysis on the isothermal decarburization behavior of GCr15 bearing steel in air， N₂+H₂+H₂O and N₂+H₂O atmospheres. The results show that in air atmosphere， no decarburization layer was observed at 700 ℃， a fully decarburized layer and a partially decarburized layer were observed at 800 ℃， and only a partially decarburized layer was present above 900 ℃. Compared with hypoeutectoid steel， GCr15 exhibits a decarburization layer covering a wide range of carbon content. Coupled with the strong sensitivity of room-temperature microstructure to the cooling rate after isothermal decarburization， the evolution of room-temperature microstructure in the decarburization layer with decarburization time is complex. The hardness method， rather than the metallographic method， is the preferred method for measuring decarburization depth. The total decarburization layer thickness increases with rising temperature and holding time， reaching 511， 690， 960， and 1 270 μm after isothermal treatment at 700， 800， 900， and 1 000 ℃ for 120 min respectively. In comparison with the N₂+H₂+H₂O atmosphere， the strong oxidizability of the N₂+H₂O atmosphere results in the oxidative ablation of the decarburized ferrite layer and even a certain proportion of the partially decarburized layer. The results of this study provide guidance for decarburization layer control during the thermal processing design of GCr15 steel.关键词：GCr15 Bearing Steel;Surface Decarburization;Heating Atmosphere;Hardness Method9|53|0更新时间：2026-04-08
- 摘要：To enhance the efficiency of the RH vacuum refining system a physical model of a 150 t RH vacuum refining system incorporating a vacuum chamber， snorkels， and ladle was established. The Euler-Euler two-fluid method was adopted for numerical simulations to systematically investigate the effects of different downcomer-to-riser diameter ratios on the circulation characteristics and refining performance of the RH device. The flow velocity at each position， flow field of the main cross-section， agitation effect on the molten steel at the ladle bottom， circulation flow rate， and mixing time under different diameter ratios（1-1.4） were analyzed for various diameter ratios. The results show that increasing the downcomer diameter significantly enhances the circulation flow rate（390 kg/s-492 kg/s）， while the mixing time decreases （286 s–269 s）. The flow field in the ladle tends to concentrate in the region between the two snorkels， the flow field in the vacuum chamber improves， and the proportion of the active region of molten steel at the ladle bottom decreases （from 39% to 19%）. Considering all factors， the optimal diameter ratio of the downcomer to the riser is 1.2， which can balance the improvement of the circulation flow rate and maintain excellent molten steel stirring capability.关键词：RH Vacuum Refining;Snorkels Structure;Molten Steel Flow Field;Stirring Performance7|41|0更新时间：2026-04-08
- 摘要：Laser polishing can effectively improve the surface quality of cold work die steel Cr12MoV. To explore the influencing factors of surface quality during laser polishing， an orthogonal experimental design was employed to formulate the experimental protocol. Cr12MoV die steel surfaces were treated using varying laser polishing parameters. Through characterization of the polished layer microstructure and geometric features such as cracks， the mechanisms underlying crack initiation and propagation during laser polishing of Cr12MoV die steel were examined. SPSS software was utilized to assess the influence patterns of laser polishing parameters on surface quality metrics of the polished regions， including remelted zone depth， polished layer depth， surface roughness， and crack formation. The results show that the surface roughness of all polished die steel specimens across experimental groups was reduced compared to the original surface， with the minimum value reaching 0.944 μm， decreased by 88.8% relative to the original surface. Crack formation was observed on the polished surfaces of die steel specimens in certain groups subjected to higher polishing power. During laser polishing of Cr12MoV die steel， laser process parameters directly effect surface quality indicators such as remelted zone depth， polished layer depth， crack dimensions， and surface roughness. Among these parameters， laser power and scanning speed are significant factors affecting the aforementioned surface quality metrics， whereas the influence of overlap rate is non-significant. Optimal selection of laser polishing process parameters can effectively enhance the surface quality of Cr12MoV die steel.关键词：Cr12MoV;Laser polishing;Process Parameter;Cracking;Thermal effect4|50|0更新时间：2026-04-08
- 摘要：In this paper， the microstructure， hardness， strength and plasticity of the Al-containing corrosion-resistant steel at different cooling rates and temperatures were studied. The corrosion resistant steel was rolled by reversible rolling mill and continuous cooling transformation （CCT） test and the high temperature tensile test were carried out. The results show that Al has a significant effect on the microstructure evolution of the corrosion resistant steel. With the increase of Al content， the ferrite phase region expands， the occurrence temperature of bainite phase region decreases， and the effect of cooling rate on the microstructure morphology is more obvious. The hardness test shows that the hardness increases significantly with the increase of cooling rate， especially when bainite transformation occurs and bainite structure is formed. When the w［Al］ content is 0.5%， the hardness of the Al-containing corrosion-resistant steel is higher than that when the w［Al］ content is 1.0 %. Moreover， the maximum force value at 1 300 ℃ for the steel with 0.5% w［Al］ is 21.9 kgf， indicating better high-temperature strength and ductility. The strength-plasitcity test reveals the difference in mechanical behavior of the two steels at different temperatures， especially the control of the brittle temperature range is important for industrial production. The fracture mechanism of the material at different temperatures is further clarified by microscopic fracture analysis. This study provides a theoretical basis and technical support for the application of the Al-containing corrosion-resistant steel.关键词：Al Content;High Temperature Properties;Phase Transformation Behavior;Microstructure2|39|0更新时间：2026-04-08
- 摘要：In order to optimize the tundish induction heating system， the influence of channel abduction angle on the distribution of electromagnetic field was studied. A three-dimensional electromagnetic field mathematical model was established to simulate the distribution characteristics of magnetic induction intensity， induced current density and Joule heat when the channel abduction angle changes in the range of 2° to 10°， taking a two-strand tundish with large nozzle spacing （5 550 mm） in a steel plant as the object. The calculation results show that under the same heating power， as the abduction angle increases， the geometric position of the channel shifts relative to the coil， resulting in a downward trend in magnetic induction intensity， current density and Joule heat， and this attenuation is most significant in the channel outlet area， indicating that the magnetic field energy loss is mainly concentrated in the second half of the channel. The magnetic field shows a stable eccentric distribution on the central section of the channel， and the electromagnetic parameters near the coil side are higher. Through comprehensive analysis， it is determined that the 2° abduction angle is the best design parameter. At this angle， the magnetic induction intensity at the near coil side can reach 0.188 T， and the overall induced current density is higher than 1.70×10⁶ A/m². Therefore， in practical engineering design， it is recommended to use 2° or adjacent small outreach angles to maximize electromagnetic coupling efficiency and improve heating performance.关键词：Tundish;Induction Heating;Angle of Channel;Electromagnetic Field;Numerical Simulation6|53|0更新时间：2026-04-08
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