最新刊期
卷 46 ， 期 2 ， 2025
- 摘要：The disc cutter is the key component of the shield machine， and it is also the most easily worn and failed component in the tunneling construction process. The wear of the disc cutter ring is mainly composed of three types of abrasive wear， adhesive wear and fatigue wear， among which abrasive wear and adhesive wear are the main wear mechanisms. In the process of rock breaking， strong extrusion and high impact make the cutter ring often wear， eccentric wear， blade， fracture， blade collapse， shedding and other failures. The cost of cutter ring loss accounts for 5%-10% of the total project， and the maintenance and replacement of cutters caused by the cutter ring failure greatly reduce the engineering construction efficiency. At present， the commonly available materials for cutter rings are DC53 and H13 steels， and their wear resistance and impact toughness depend on the type， morphology， size， quantity， distribution and matrix structure characteristics of carbides in those steels. In order to inprove the performance of the disc cutter ring， domestic and foreign scholars have carried out a series of studies on the optimization of alloy design for the cutter ring， the one-time forming preparation of the cutter ring， the induction heat treatment preparation of the gradient performance cutter ring， and the development of the bimetallic composite cutter ring， which provides a strong support for the performance enhancement of the cutter ring.关键词：Shield Cutter Ring;Wear Failure;Carbide;Component Optimization;Composite Cutter Ring12|2|0更新时间：2025-05-09
- 摘要：Steel for ultra-low-temperature pressure vessel is steel specifically applied to liquid nitrogen （-196 ℃） and below， and requiring sufficient mechanical strength and toughness under extreme low-temperature conditions. In general， the strength and hardness of steels increase as the temperature decreases， but at the same time this is accompanied by a significant increase in the risk of brittle fracture and a decrease in plastic deformability， creating significant difficulties and challenges in their design and application. Based on the demand for high strength and toughness of ultra-low-temperature pressure vessels at temperature of -196 ℃ and below， and in response to the bottleneck problem that it is difficult to combine high toughness and high strength of steel at ultra-low temperatures， the performance characteristics of steel in ultra-low-temperature environments are introduced from the classification of steel and the current status of the research， respectively. In addition， new methods， processes and research and development progress of steel toughening in ultra-low-temperature environments are summarized， focusing on the analysis of low-temperature toughness mechanisms and strengthening strategies of several typical ultra-low-temperature steels， as well as their tough-brittle transition mechanisms， which mainly include martensitic phase transformation， dislocation motion and twin crystal formation and other micro-mechanisms. The effects of factors such as chemical composition， crystal structure and grain size on the low-temperature toughness of steel are summarized. Finally， based on the existing research results， the preparation and strengthening of steels for ultra-low-temperature pressure vessels are prospected.关键词：Ultra-low Temperature Pressure Vessel;Low-temperature Steel;Low Temperature Toughness;Toughness-ductility Transition;Low Temperature Phase Transition;Mechanical Property3|1|0更新时间：2025-05-09
- 摘要：China has entered a new stage of economic development while facing the “double carbon” development strategy， the development of full waste steel electric arc furnace steelmaking is China's iron and steel industry to carry out structural adjustment of steel production process is an inevitable choice， For a long time the production efficiency of electric arc steelmakin is lower than that of converter steelmaking is a key constraint on the development of its key factors， exploring the key factors affecting the production efficiency of electric arc furnace steelmaking is conducive to the healthy development of electric arc steelmaking production；By establishing the calculation formula of the production efficiency of electric arc furnace， analyzing the key factors affecting the production efficiency of electric arc furnace steel production， and then confirming with the actual production of statistical data corroboration， the result show that， China's modern electric arc furnace steel production efficiency has made great progress. Through equipment large-scale and efficient smelting technology， it can make the electric arc furnace steelmaking production efficiency with the same tonnage converter steelmaking production efficiency （200 t/h）. The decisive factor affecting the production efficiency of electric arc furnace steelmaking is the electric arc furnace steelmaking process of energy supply power. In the impetus of material conversion， only improve the electric arc furnace steelmaking process total energy supply can not directly improve its productivity， only to improve the electric arc furnace in the process of energy supply power， can input energy into improve the impetus of material conversion.关键词：Electric Arc Furnace Steelmaking;Productivity;Factors Analysis;Energy Power5|3|0更新时间：2025-05-09
- 摘要：Low-alloy high-strength fastener stee which is widely used in automobiles， high-speed rail， aviation， aerospace， defense， and other fields due to its excellent mechanical properties and in line with the trend of lightweight development. In recent years， with the continuous progress of industrial technology and the increasing requirements for material performance， the development of low-alloy high-strength fastener steel has shown a new trend. It is expected that the actual practical application strength level of fasteners will exceed grade 16.8. In this paper， through the typical application of fasteners products， firstly it points out that fasteners require good mechanical properties， processing performance， and heat treatment performance. Specific performance and application environment-based evaluation is carried out to ensure safety and reliability. Secondly， this paper analyzes the history and trends of high-strength fastener steel， including high-strength fastener steel， ultra-high-strength fastener steel， and non-quenching high-strength fastener steel， and discusses the role of composition in enhancing steel properties. Then， the paper introduces the research and application of key technologies for high-strength fastener steel， focusing on the design of steel composition， control of non-metallic inclusions， resistance to delay fracture and steel manufacturing technology. The paper also discusses the impact of related content on product performance， in order to enhance the comprehensive performance of fasteners， reduce their hydrogen embrittlement sensitivity， and meet the requirements of intelligent manufacturing， it is necessary to keep the ［H］ content in steel below 1×10-6， further reduce the size of inclusions， and control the fluctuation range of main elements in steel more precisely： w［C］±0.01%， w［Si］±0.02%， w［Mn］±0.02%， w［Mo］±0.01%， the development of low hydrogen embrittlement sensitive bainitic steel is rapidly advancing.At the same time， while environmental regulations become increasingly strict， the concept of green manufacturing and recyclability is gradually incorporated into the production of low-alloy high-strength fastener steel，and the proportion of electric furnace steel smelting and hydrogen metallurgy varieties has significantly increased..Finally， the paper looks ahead to the future of low-alloy high-strength fastener steel， which will move towards high performance， low cost， environmental protection， and intelligentization. With the progress of science and technology and changes in market demand， low-alloy high-strength fastener steel will play an important role in a wider range of fields and provide a solid material basis for the development of modern industry关键词：High Strength;Fasteners;Bolts;Delayed fracture;Hydrogen Embrittlement;Light Weight7|3|0更新时间：2025-05-09
Overview
- 摘要：As the national vigorously develops offshore wind power， the power of wind turbines is getting bigger and bigger， and the strength requirements for wind power fasteners are also increased， and high-strength fasteners have been more widely used.Steel grade 42CrMo is widely used in the manufacture of wind power fasteners with good mechanical properties after tempering， but it cannot meet the performance requirements of M64-M72 large size fasteners. For steel grade 42CrMoM with
- 摘要：Based on domestic and abroad market demands，this article introduces the development process of pre-hardened and ultra-thick 1.2311 steel plate used for plastic mold steel.Experimental study on continuous phase transformation behavior of 1.2311 steel was conducted，and a static continuous cooling transformation curve was drawn.By KR pretreatment→120 t converter （smelting using slag retention method can control carbon content within 0.20%-0.30%）→LF（refining argon blowing time ≥60 minutes）→VD （vacuum degree ≤67 Pa，vacuum holding time≥20 minutes）→450 mm slab continuous casting（low superheat of 8-15 ℃，low pulling speed of 0.45 m/min）→Slab heating→5 000 mm mill rolling （the sum of the last three pass reductions is ≥140 mm for rough mill）→860-890 ℃ normalizing process→ACC controlled cooling （combination of water cooling and air cooling）→550-610 ℃ tempering process，the pre-hardened and ultra-thick steel plate for plastic mold 1.2311 with a specification of ≥150 mm was successfully developed.The results show that a Brinell hardness deviation of ≤15HBW across the entire thickness，resulting in good uniformity of hardness，the ultrasonic testing of the plates meets the requirements of Level I in GB/T2970―2016.All comprehensive performance indicators meet the development requirements.关键词：1.2311 steel;Pre-hardened;CCT Curve;Hardness3|1|0更新时间：2025-05-09
- 摘要：High quality forged steel for cold rolling roller plays a crucial role in improving the quality of cold-rolled sheets and enhancing production efficiency. Improving the innovation of electric slag process technology for cold rolling roller is of great significance for enhancing the metallurgical quality of high-quality forged steel for cold rolling roller. In depth research and analysis of the electric slag process technology， with a focus on analyzing the shallow flat metal melt pool and solidification homogenization of electric slag remelting. Three aspects of electric slag process technology innovation research were determined： slag temperature compensation melting rate， rapid cooling with chilled water supplementation， and strengthening slag pool stirring with filling ratio. In the production practice， adding slag temperature compensation to the melting speed controls ， and the slag temperature slag temperature was controlled within the range of 1 580 ℃-1 680 ℃， which realized real-time performance of shallow flat metal melt pools at the micro level； The rapid cooling was optimized by supplementing the chilled water through Venturi fittings，and the cooling water temperature of the crystallizer reached a linear change of ±5 ℃， which ensured the consistency of the cooling effect at the bottom of the electric slag ingot and realized the stability of the shallow flat metal melt pool at the macroscopic level； The parameter of electric slag filling ratio was adjusted to 0.65 ± 0.05， which strengthened the stirring effect of metal droplets passing through the slag pool for refinement and homogenization， and achieved the metallurgical effect of electric slag solidification homogenization. The process of "slag temperature compensation+chilled water supplementation" was adopted to obtain a shallow flat metal melt pool. The filling ratio strengthened the slag pool stirring and improved the homogenization of electric slag solidification. After final product testing and use， the metallurgical quality of the cold rolling mill was significantly improved.关键词：High Quality Forged Steel for Cold Rolling Roller;Shallow Flat Metal Melt Pool;Solidification Homogenization;Slag Temperature Compensation Melting Rate;Refrigerated Water Replenishment for Rapid Cooling;Strengthening Slag Pool Mixing with Filling Ratio3|2|0更新时间：2025-05-09
Product Research and Development
- 摘要：In order to improve the quality of vertical continuous casting 40Mn2 square bloom ， a four-quarter tangential swirl nozzle was proposed， using a Particle image velocimetry technique， the molten steel flow and slag interface behavior at different casting speeds and nozzle immersion depths were studied in a steel plant's bloom mold with 410 mm × 560 mm vertical continuous casting section. The results show that the fluidity of the mold powder at the interface of steel slag is poor when the depth of the nozzle is 90 mm and the casting speed is 0.25 m/min， and the slag entrapment occurs when the casting speed is 0.35 m/min and 0.45 m/min，When the immersion depth of the nozzle is 100 mm， the fluidity of the mold powder at the interface of steel slag is poor while the casting speed is 0.25 m/min， and at 0.35 m/min casting speed ， the inclusion will float upwards. The interface of steel slag is active and there is no slag entrapment， and slag entrapment will occur at 0.45 m/min casting speed . When the immersion depth of the nozzle is 110 mm， the fluidity of the mold powder at the interface of steel slag is poor while the casting speed is 0.25 m/min. When the casting speed is 0.45 m/min， the slag entrapment will occur. When the casting speed is 0.35 m/min， no slag entrapment will occur， compared with the same casting speed and 100 mm immersion depth of nozzle， it is unfavorable to the floating of inclusions. Combined with the actual production practice， the optimum operating parameters of the vertical continuous casting bloom mold are the depth of nozzle immersion 100 mm and casting speed 0.35 m/min.关键词：Swirl Nozzle;Vertical Continuous Casting;Slag Interface;Bloom Mould;Flow Field4|1|0更新时间：2025-05-09
- 摘要：In order to investigate the influencing factors of the precipitation of σ phase in the solidification structure of FeCr16 corrosion-resistant soft magnetic alloy during electroslag remelting process， a series testes has been conducted to study the solidification process and precipitation of FeCr16 corrosion-resistant SMA （Soft Magnetic Alloy） from 1 600 ℃ to 1 400 ℃ at different cooling rates of 5， 10， 20 ℃/min by using 1 LM21H-SVF17SP LSCM （Laser Scanning Confocal Microscopy）. Meanwhile combining with thermodynamic calculation via JMatPro software， the relationship between segregation of Cr and σ-phase precipitation was studied. In addition， the test was performed with different melting rates during ESR process ， and the relationship between σ-phase precipitation and ESR speed was also investigated. The results showed that while the cooling rate of solidification was low， the segregation degree of Cr element in the alloy was relatively high. With the increase of cooling rate， the maximum segregation rate and average segregation rate of Cr element both decreased； The segregation of Cr element provided favorable kinetic conditions for the precipitation of σ-phase. The higher ESR speed was， the slower the solidification rate， the higher the segregation， the more easily the σ-Phase precipitated. When ESR speed was set as 3.5 kg/min-4.5 kg/min， no σ Phase was found in the microstructure of ESR ingot after heat treatment， while the ESR speed was adjusted to 5.0 kg/min-6.0 kg/min， σ-Phase precipitation was detected. The optimal ESR speed was 3.5 kg/min-4.5 kg/min.关键词：FeCr16 Corrosion-resistant SMA;Cooling Rate;ESR Speed;Segregation;σ-Phase2|1|0更新时间：2025-05-09
- 摘要：In present paper，the control technology of aluminum content and inclusion composition was analyzed for high-silicon and aluminum-controlled steel by technological test. The results showed that content of Al in steel can be controlled within 0.0040% by using low basicity slag with alkalinity below 1.5，while the Al content is higher than 0.006% by using high basicity slag with basicity 2.5 - 3.5. The decrease of Al2O3 content in slag is beneficial to decrease the amount of Al increase in molten steel.The oxide inclusion component in low basicity slag steel is SiO2-MnO-Al2O3-MgO-CaO series ， which achieves the control of inclusion plasticization. The oxide inclusion component in high basicity slag steel is Al2O3-SiO2-MgO-CaO series with high Al2O3 content， and the plastic deformation ability of the inclusion material is insufficient. High clean steel with oxygen content less than 0.001 2% and fine inclusions can be obtained after RH control processing， although deoxygenation effect of the steel with low basicity slag is poor in the refining process.关键词：Slag Basicity;Aluminum Content;Composition of Inclusions;Plastic Inclusions2|1|0更新时间：2025-05-09
- 摘要：In view of the large use of calcium fluoride in LF refining process， an optimization scheme of fluorine-free refining slag system is proposed.Calculated by FactSage software， the optimal composition of the fluorine-free refining slag was determined to be： the mass fraction of CaO：52%-58%， SiO2：8%-12%， Al2O3：25%-35%， MgO：5%-7%， with a basicity of 4-6 and a （CaO）/（Al2O3）ratio of 1.5-2.0. Compared to the original slag system， the new fluorine-free slag system can be completely melted at 1 500 ℃， reducing the melting temperature by 60 ℃， and has a Mannesmann index of approximately 0.15， which meets the performance requirements of LF refining slag. Using the optimized slag system in the actual production， the application of the optimized slag system resulted in a 24% reduction in total oxygen content， a 21.3% reduction in nitrogen content， a 22.9% reduction in the number of inclusions during refining process， and a 22.4% reduction in the number of inclusions during the tundish process compared to the pre-optimization slag system. The results demonstrate that the fluorine-free slag system not only significantly improves the cleanliness of molten steel and enhances the quality of steel but also aligns with current development trend of environmental protection and energy saving， reducing the corrosion of metallurgical equipment and environmental pollution， thus offering significant environmental protection and economic benefits. This study provides a viable solution for steel enterprises to achieve efficient refining processes and significantly improve the cleanliness and quality of steel without using calcium fluoride.关键词：45 Steel;Inclusions;Refining Slag Optimization;CaF23|1|0更新时间：2025-05-09
Smelting and Solidification
- 摘要：The effect of different deformation on the microstructure evolution and properties of 5.3 mm thick GH4169 alloy plate was studied. The grain size and grain boundary characteristics were observed by optical microscope and EBSD analysis. The tensile strength， plasticity and other mechanical properties of the materials treated with two deformation amounts were compared， and the relationship between processing， microstructure and properties was established. The results show that the grain size and microstructure are significantly affected by different deformation amounts. Hot rolled plate after processs A cold deformation （（thickening1.4 mm） of the grain size is 6 μ m， the small angle grain boundary （<10°） is 73.2%， the large angle grain boundary （> 10 °） is 26.8%， too fast deformation rate makes uneven deformation， the formation of mixed crystal， the proportion of deformation grain is 85.3%， substructure is 5.6%， recrystallization grain rate is 9.1%， After cold deformation of process B （0.7 mm thickening）， the grain size is 35 μ m， the proportion of small angle grain boundary （<10 °） is 51.6%， and the proportion of the large angle grain boundary （> 10 °） is 48.4%， the microstrusture is uniform， the proportion of twins is large， the substructure is 95.7%， the deformed grain is 3.4%， and the recrystallization grain proportion is 0.9%. The room temperature tensile strength and yield strength of cold deformation process A are significantly higher than that of cold deformation process B， but the elongation rate is lower than process B， and the properties of the final plate is attributed to the smaller grain size and higher substructure density of process A.关键词：Deformation;GH4169;Microstructure;EBSD;Mechanical Properties6|2|0更新时间：2025-05-09
- 摘要：This study optimized the ultrafine grain forging process of 18Ni （250） martensitic aging steel for specific application requirements in deep and low temperature environments， aiming to improve the plasticity and toughness of the material under deep and low temperature conditions. The study analyzed the behavior of materials during hot deformation process and the influence of deformation process on microstructure through hot deformation method， observed the microstructure after hot deformation， and established the constitutive equation and hot working diagram between material rheological stress， deformation temperature， and strain rate. Finally， the optimal heat treatment process area was determined， which is the range of deformation temperature and deformation rate. Research has shown that when the deformation temperature is higher than 1 050 ℃ and the deformation is 30 percent， the material exhibits austenite grain recrystallization phenomenon. When the deformation temperature is 1 150 ℃， the grain structure tends to refine. Based on the thermal deformation equation and thermal processing diagram with deformation temperature between 850 ℃-1 150 ℃ and strain rate within the range of 0.01 s-1-10 s-1， the ideal thermal processing zone of the material was obtained， which is the deformation temperature range of 1 050 ℃-1 150 ℃ and the strain rate range of 0.01 s-1-10 s-1.关键词：Hot Deformation;18Ni（250） Steel;Recrystallization;Grain Refinement;Intrinsic Equation7|3|0更新时间：2025-05-09
- 摘要：Taking 9Ni steel plate as the object of analysis， the different heat treatment processes of 9Ni steel plate in the head manufacturing process were simulated in the laboratory， and the properties of the test plate in hot-formed state，hot-formed state+QT state，hot-formed state+NNT state and the corresponding post-welded stress relieving state were investigated respectively.The results show that： 20 mm thick 9Ni steel test plate after 930 ℃ high-temperature hot forming，the base material structure was completely destroyed，its reverse austenite basically disappeared，the yield strength decreased by 100 MPa，and the maximum impact energy absorbed at -196 ℃ was only 10 J，it must be re-heat treated to restore the mechanical properties. After hot forming， the mechanical properties of the test plate were restored using the NNT process. Compared with the QT recovery process， the -196 ℃ impact absorption energy， room temperature yield strength， and room temperature tensile strength were significantly lower. The reason for this was that the NNT process test plate contained significantly lower content of inverted austenite than the QT process test plate. Therefore， the mechanical properties restored by QT process were good and stable. After the elongation cold deformation of 2.5%-7.5%， when the aging treatment temperature reached 250 ℃， the average aging sensitivity coefficient of 20 ℃ and-196 ℃ shock absorption energy was 0.62% to 10%， and the aging sensitivity of the base material was low；When the aging treatment temperature reached 540 ℃， the average aging sensitivity coefficient was 13.93% to 30.63%. Although the aging sensitivity of the base material slightly increased， the impact absorption energy showed a small decrease， but all were greater than 180 J. The surplus of impact absorption energy of the base material was still relatively large.关键词：9Ni Steel Plate;Hot Forming;Post-welded;Stress Relief;Reverse Austenite;Impact Energy Absorption5|1|0更新时间：2025-05-09
- 摘要：The large end face continuous casting billet is prone to a series of internal quality problems such as centre sparsity and shrinkage holes， irregular distribution of centre coarse equiaxial crystal zone when rolling large-size bars. Designed four different BD mills （BD is abbreviated for English blank， 1250 double roll reversible rolling mill used in this test） the open billet process on 42CrMo steel 410 mm × 530 mm specifications of continuous casting billet rolled to 255 mm × 255 mm size process to study， first using finite element simulation software for simulation of the rolling process， and then after the verification of industrial tests on the final
- 摘要：The development and application of ultra-high strength spring flat steel is of great significance in achieving automotive lightweight. Understanding the continuous cooling transformation behavior of this type of steel aids in developing its post-hot rolling cooling and quenching-tempering processes. On the basis of mechanical property testing， this study focuses on a newly designed ultra-high strength flat spring steel， 50SiMnCr， to investigate the effect of cooling rate on the microstructure and hardness of experimental steel by a combination of metallographic-hardness and thermal expansion method， thereby constructing continuous cooling transformation （CCT） curves. The results show that the strength and ductility of 50SiMnCr steel meet the requirements of the 2 000 MPa level， with phase transition point Ac1=721 ℃， Ac3=758 ℃， Ms=220 ℃ and Mf=103 ℃. Ferrite and pearlite transformation occurs when the cooling rate is 0.05 ℃/s-0.5 ℃/s. Bainite transformation takes place when the cooling rate is increased to 1 ℃/s. Martensite transformation happens when the cooling rate is above 2 ℃/s. The hardness of the this steel increases with increasing the cooling rate.关键词：50SiMnCr steel;2000 MPa Grade Spring Steel;Continuous Cooling Transformation;Microstructure;Hardness10|5|0更新时间：2025-05-09
- 摘要：Haynes 230 is an important candidate material for high temperature components in ultra-high temperature gas-cooled reactors， concentrating solar power and advanced ultra-supercritical coal-fired generating plants.In order to establish the alloy microstructure control criterion， it adopts the hot-rolled forming plate and adjusts the solid solution temperature，the law of microstructure evolution of the behavior of precipitation phase dissolution and the change of grain size during solution treatment were studied，The results showed that the hot-rolled plates were composed of equiaxed austenitic grains with the average grain size of 32 μm. the main precipitation phase was detected to be M6C carbide and the metal cluster M was composed of W and Mo. The carbide content and particle size of M6C varied little and the austenitic grains coarsened little during solution treatments in the temperature range of 950-1 150 oC. With the increasing of solid solution temperature to 1 180-1 200 oC， the carbide content of M6C decreased， the particle size decreased， and the grain was coarening；At 1 230 oC and 1 250 oC， the dissolution of M6C and the coarsening of grains became obviously with the average grain size to be 142 μm and 201 μm， respectively. Tensile strength at room temperature and 750 oC decreased slightly with the increasing solution temperature ， while tensile strength at 900 oC increased. The grain size and the related solution temperature was recommended to be controlled in rang of 76-142 μm and 1 200-1 230 oC based on the present experimental investigation， respectively.关键词：Haynes 230 Alloy;Solution Treatment;Grain Size;Carbide4|3|0更新时间：2025-05-09
Forming and Phase Transition
- 摘要：The effect of microstructure evolution on thermal conductivity of alloy 690 electrode was studied according to the working conditions of electrode materials in Joule furnace. Typical compositions of alloy 690 were smelted using pure metal and samples of 690 in different states were obtained by forging， hot rolling and cold rolling. The grain size， grain boundary type， grain boundary distribution， dislocation density， and precipitated phase species of the 690 samples in different states were tested by means of scanning electron microscope （SEM）， energy dispersive spectrometer （EDS）， electron back scatter diffraction （EBSD）， X-ray diffraction （XRD）， and the measurement of thermal conductivity by flash method. The microstructure evolution of alloy 690 materials for joule furnace electrodes in different processing states and its influence on thermal conductivity were clarified. The results show that， alloy 690 in the hot rolled state has the highest thermal conductivity， followed by the wrought state， while alloy 690 in the cold rolled state has the lowest thermal conductivity. The reasons for this are： （1） The grain size and total grain boundary area of 690 alloy change significantly under different deformation processes， and the cold-rolled state alloy has the smallest grain size and the highest total grain boundary area； （2） The grain boundaries of the forged and cold rolled state 690 alloys are dominated by small-angle grain boundaries， The low ΣCSL grain boundaries of the three states of alloy 690 are dominated by Σ3 grain boundaries；（3）The cold-rolled state 690 alloy has the highest dislocation density.（4）The main reason for the large decrease in thermal conductivity of alloy 690 in the cold rolled state is the high grain boundary total area ratio and the high dislocation density after cold rolling.关键词：Alloy 690;Joule furnace;Microstructure;Thermal Conductivity16|3|0更新时间：2025-05-09
- 摘要：A certain auto parts manufacturer uses alloy cold heading steel SCM435 hot-rolled wire rod with a specification of
Application and Service
- Technical support is provided by Beijing Founder electronics co., LTD 鄂ICP备2022000839号
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
- Total Visits：35684
0