最新刊期
卷 46 ， 期 5 ， 2025
- 摘要：The microstructure， fatigue fracture morphology， mechanical properties， and torsional fatigue life of the traditional seamless steel pipe 26CrMo for non-dig drilling pipe and the economical high-strength seamless steel pipe AGCY27 for non-dig drilling pipe were analyzed using optical microscopy， scanning electron microscopy， transmission electron microscopy， and mechanical tests. In terms of composition design， compared with traditional drilling pipe， economical drilling pipe removes precious metal Mo and reduce Cr content， appropriately increases Ti alloy， and increases Si content. The results show that the Ac3 point of the traditional drill pipe is 803 ℃， and the Ac3 point of the economical drilling pipe is 860 ℃. Through the heat treatment process of quenching+490 ℃ tempering， both meet the requirements of API 5D-2020 standard for 135 ksi grade drilling pipe. Under the heat treatment process in this experiment， compared with traditional drill pipe， economical drilling pipe has better impact toughness and fatigue performance， with an impact energy of over 109 J and an average fatigue cycle of 36 107 times. The microstructure of traditional drilling pipe is tempered martensite， while the microstructure of economical drilling pipe is tempered sorbite. The proportion of small angle grain boundaries in economical drilling pipe is 21%， while that in traditional drill pipe is 29%. Economical drill pipe has more large angle grain boundaries， and their microstructure is conducive to obtaining better comprehensive mechanical properties. The precipitation phase of traditional drill pipe is Cr alloy cementite， which is beneficial for improving their mechanical properties. The precipitation phases of economical drilling pipe is mainly TiCN， TiC， and TiO， which play a role in constraining the growth of austenite grains and improving the comprehensive mechanical properties of the product.关键词：Economic;Non-dig Drilling Pipe;Fatigue Propertie;Seamless Steel Pipe60|7|0更新时间：2025-09-11
- 摘要：In order to realize the domestic production of UNS N09 925 alloy in the oilfield service industry， the "VIM+VAR" process was successfully used to smelt
Product Research and Development
- 摘要：In vacuum induction melting （abbreviated as VIM）， the quality of crucible furnace lining is directly related to the metallurgical quality， production safety and cost. The test was carried out to research from the aspects of lining material selection， manufacturing method and sintering process and so on， and the critical factors and rules affecting the crucible quality were analyzed. The results show that compared with Mgo based material， Al2O3 based furnace lining can reduce cracking and peeling； With using automatic furnace construction instead of manual operation， the furnace lining had higher density and uniformity， and better thermal hardening. Appropriately reducing heating rate to 40 ℃/h-60 ℃/h and extending insulation time during furnace lining sintering achieved uniform temperature distribution， promoted water vapor discharge， and sintering at 1 650 ℃. Then effective process were proposed to improve the service life of VIM lining， and metallurgical quality effect.关键词：VIM;Furnace Lining Material;Crucible life;Sintering Process57|6|0更新时间：2025-09-11
- 摘要：100 t dephosphorization converter carried out the top blowing CO2 industrial test by JISCO stainless steel branch ， analyzed the dephosphorization converter top blowing mixed with different proportions of CO2 on the smelting end of the slag w［FeO］， dephosphorization rate， molten iron yield， steel temperature and lime block consumption. In this paper， five groups of test schemes were set up， and the proportions of top-blowing CO2 mixing were 5%， 10%， 15% and 20%， and the control test schemes was added at the same time. The test results show that： the top blowing CO2 mixing can improve the thermodynamic and kinetic conditions of the reaction in the dephosphorization converter furnace， and improve the efficiency of dephosphorization； when the top blowing CO2 mixing ratio is 15%， w［FeO］ in the slag reaches 19.95%；The efficiency of dephosphorization reaches 82.82%； the rate of molten iron yield reaches 97.8%； the top blowing CO2 mixing ratio of 15% achieves the optimal effect.关键词：Dephosphorization Converter;Dephosphorization Rate;CO2 top Blowing;CO2-O2 Mixture;Yield of Molten Iron10|10|0更新时间：2025-09-11
- 摘要：In order to control the appropriate nitrogen content of steel and better meet the processing performance requirements of industrial wire rods， industrial tests were carried out in combination with Yonggang's 120-ton top-bottom reblowing converter→argon blowing station→refining furnace→eight-machine eight-flow billet continuous casting machine and production process conditions. On the basis of low-cost production， by adjusting the converter blowing， steel tapping process， refining and continuous casting production process， nitrogen content samples were taken at different production operation stages for analysis and exploration of the influence of different production processes and operating parameters on the content of molten steel ［N］， and then through solidification converter smelting later oxygen pressure 0.95 MPa-1.0 MPa， pressing gun time 50 s-70 s， ensuring the conversion furnace inversion rate and appropriate carbon content at the end of the converter， weak deoxidation process of molten steel during tapping process， continuous casting machine protection pouring and other operational measures The content of ［N］ in different steel grades of molten steel was controlled in each production process， and the w［O］ of non-refined low-carbon steel finished products is controlled within （110~150） × 10-6， w［N］ is controlled within 27 × 10-6， and the finished product w［N］ of desulfurization steel is controlled below 38 × 10-6， which was an average decrease of 17.8 × 10-6 compared to before the process improvement， and the product quality stability was well controlled.关键词：Nitrogen Content;Converter Blowing;Success Rate of One-time Pouring;Weak Deoxidation;Protective Casting8|4|0更新时间：2025-09-11
- 摘要：This article studies the effect of different refining slag basicity on the cleanliness of GCr15SiMn bearing steel by combining laboratory slag-steel equilibrium experiments and theoretical calculations. Slag-steel equilibrium experiments were conducted with three different refining slag basicity ratios （6.32，5.28 and 4.27 respectively） and steel samples with the identical chemical composition.The experimental results show that the experimental steel group with a basicity of 4.27 had the lowest oxygen and magnesium contents （0.000 6% and 0.000 9%， respectively）， and the smallest number density of inclusions （0.31 per mm²）， demonstrating excellent performance in controlling molten steel cleanliness. Additionally， the changes in SiO2 and FeO in the corresponding slag for this experimental group were also the smallest， indicating that reducing the initial refining slag basicity helps to quickly achieve equilibrium in the slag-steel metallurgical reaction and reduce the formation of inclusions in the steel. Further calculations using the slag-steel equilibrium thermodynamic model confirmed that reducing the refining slag basicity can increase the logarithmic ratio of SiO2 to Al2O3， inhibit the reaction between Al and SiO2 in the slag， and reduce the transfer of oxygen from SiO2 to the molten steel. Finally， the experimental results were applied to factory practice. The results showed that appropriately reducing the refining slag basicity can significantly improve the cleanliness of the GCr15SiMn molten steel. This research provides strong theoretical support and guidance for the industrial practice of smelting high-cleanliness bearing steel.关键词：GCr15SiMn Steel;Cleanliness;Refining Slag Basicity;Slag-steel Reaction;Thermodynamics28|10|0更新时间：2025-09-11
- 摘要：Due to the good uniformity， toughness and machining properties of equiaxed crystals， the cracking risk can be reduced in the subsequent processing of 4J36 Invar ingot， however， most of the previous studies focused on the solidification process of steel and alloy by using CAFE model， and the influence of nucleation parameters on the solidification structure of 4J36 ingot has not been reported. Therefore， the solidification process of 4J36 ingot was simulated by CAFE model， and the influences of nucleation parameters on the solidification structure of ingot were discussed. The experimental result was in agreement with the simulation result， which verified the accuracy of the model and showed that it could be effectively applied to the simulation and prediction of solidification structure of 4J36 invar ingot. The results show that when the body maximum nucleation density increases from 2×106 m-3 to 2×109 m-3， the columnar crystal region will decrease， the central equiaxed crystal range will expand， the grain number will increase by 97.6%， the average grain area will decrease by 97.6%， the maximum grain area will increase by 98.6%， the average grain radius will decrease by 89.3%， and the minimum grain area will remain unchanged. When the surface maximum nucleation density increases from 2×105 m-2 to 2×108 m-2， the crystal structure of the ingot will not change significantly， the grain number will increase by 13.4%， and the average grain radius will decrease by 10.3%. When the body maximum nuclear super-cooling degree increases from 0.5 K to 4 K， the columnar crystal region will increase， the central equiaxed crystal range will decrease， the grain coarsening is obvious， the grain number will decrease by 55.2%， and the average grain radius will increase by 36.1%. When surface maximum nucleation super-cooling degree increases from 0.5 K to 2 K， there will be no obvious effect on the crystal structure and grain size of the ingot.关键词：4J36 Invar Alloy;Solidification Structure;Nucleation Parameter;Numerical Simulation13|10|0更新时间：2025-09-11
- 摘要：Research was conducted on the key metallurgical technologies in the smelting process of 1Cr13 stainless steel based on the ANS-OB process. Through thermodynamic and kinetic analysis of the process， the effects of steel tapping temperature， refining temperature， gas flow rate， smelting time， and reduction deoxidation on the smelting process were studied， and the key technical indicators for 1Cr13 stainless steel smelting were clarified. The results indicated that the tapping temperature of the converter and intermediate frequency furnace should be higher than 1 600 ℃ to ensure the subsequent refining temperature and reduce the temperature or composition mismatch caused by the adding alloys. The refining temperature range of ANS-OB process was 1 650 ℃-1 700 ℃， and its oxygen supply intensity gradually decreased from 0.8 m3/（t·min） to 0.4 m3/（t·min）， while gradually increasing the argon supply intensity. Specifically， the flow ratio of O2 to Ar was 1∶（0.86-2.16）， and the main oxygen blowing time was 30 minutes-34 minutes， reducing the C content in the molten steel to below 0.08%. Then， ferrosilicon was used for reduction deoxidation， with a dosage of 10 kg/t and an Ar supply intensity of 0.5 m3/（t·min） maintained to reduce the O content in the molten steel to below 0.003 0%. Finally， add alloys such as ferrosilicon and manganese iron to adjust the composition of the molten steel. Smelting was carried out according to the established process plan， and good industrial test results were achieved.关键词：ANS-OB;Stainless Steel;Thermodynamics;CO Partial Pressure;Temperature3|1|0更新时间：2025-09-11
Smelting and Solidification
- 摘要：Cold heading steel SCM435 high-speed wire is easy to undergo bainite transformation in the cooling stage. It is very important to explore the temperature field and phase precipitation process in the Stelmor air -cooling line for the quality control of the final product . By establishing the finite difference equation of temperature field， heat transfer coefficient model and phase precipitation equation， the bridge between the rolling production process and the rolling piece temperature and organization relationship is built， and the calculation of the temperature field and phase precipitation evolution law of SCM435 rolled cold heading steel is realized.The calculation results show that the initial billet enters the rolling line at a temperature of 900 ℃， with an opening surface temperature of 854 ℃ and a surface temperature of 710 ℃ when entering the spinning machine. The temperature difference between the core and surface is 41 ℃， and the maximum temperature drop through water is 234 ℃. During the cooling stage of the air-cooled line， the phase precipitation curves under two different cooling conditions were calculated by adjusting the opening and closing of the insulation cover. The results showed that slow cooling can significantly promote the precipitation of ferrite and pearlite while suppressing the precipitation process of bainite.关键词：High-speed Wire;Temperature Field;Phase Precipitation;Finite Difference Equation;TTT Curve195|7|0更新时间：2025-09-11
- 摘要：Compared with hot extrusion process with the long cycle， low yield， and high cost， the production of UNS N08811 iron-nickel-based alloy pipes using hot piercing process can significantly reduce production costs. However， surface transverse cracks are prone to occur during the piercing process， which affects the product qualification rate and safety of use. To reduce the piercing defect rate of this product， JMatPro software was used to analyze the thermal processing performance of the material， and Simufact software was used to simulate the temperature and stress changes during the hot piercing process of N08811 iron-nickel-based alloy pipe billet； Based on spot technology tests， the suitable outlet heating temperature for hot piercing of this material was 1 130 ℃-1 150 ℃； During the piercing process， it was necessary to adjust the steel extract rhythm and control the final rolling steel temperature not to exceed 1 220 ℃； It was necessary to quickly pass through the temperature range of 660 ℃-850 ℃ to reduce the formation of harmful phases when heating and cooling； In order to reduce the temperature gradient and stress changes during the piercing process， the entire deformation process from the top contact with the pipe billet to the completion of piercing should be extended， so that the stress during the rolling piercing rounding process of the pipe billet was more uniform， and the temperature and stress curves were smoother； By improving the design of the piercing cone， reducing the curvature of the cone arc section， increasing the length of the cone， increasing the angle of the straight section， reducing the biting ellipse coefficient， and lowering the rolling speed， the hot piercing defect rate of N08811 iron-nickel-based alloy pipe billet can be effectively reduced， ensuring the surface quality of the product.关键词：UNS N08811;Iron-nickel Base Alloy;Seamless Pipe;Hot Piercing9|3|0更新时间：2025-09-11
- 摘要：TH550-NQ-Ⅱ weather-resistant special welding steel wire rod added Ni， Cr， Cu and other alloying elements， there are more quenching structures in the hot-rolled wire rod structure， the quenching structure accounts for about 40%， the mechanical properties of the full length wire rod fluctuate greatly， the tensile strength of the full length wire rod fluctuates above 80 MPa， downstream customers are prone to fracture when directly drawing， and the proportion of broken wires is about 3%. Part of the wire rod needs to be annealed and drawn before it can be used.In order to reduce the quenching structure in the wire structure and solve the problem of the large fluctuation of mechanical properties of the wire rod， the CCT curve of the TH550-NQ-Ⅱ wire rod is measured by thermal dilatation instrument. After analyzing the CCT curve of the TH550-NQ-Ⅱ wire rod， the duplex-phase rolling test of the TH550-NQ-ⅱ wire rod is carried out. The reducing and sizing temperature of the test wire rod was controlled at 820 ℃， and the spinning temperature was controlled at 810 ℃. With the opening of the insulation cover ， the conversion rate of wire rod to F or P is accelerated， the time to complete the phase transition of F and P is reduced， the proportion of hardened structure of wire rod is reduced to about 27%， the tensile strength fluctuation of full length wire rod is reduced to less than 40 MPa， and the proportion of broken wire is reduced to less than 0.5% during customer drawing， which meets the customer's demand for less annealing or non-annealing drawing.关键词：Weather Resistant Special Welding Steel;TH550-NQ-ⅡWire Rod;Two-phase Zone Rolling;Metallographic Structure;Drawing Performance191|6|0更新时间：2025-09-11
- 摘要：Extra-thick plates of marine steel are widely used in marine engineering and are produced by microalloying and heat treatment process. The extra-thick plate needs to be slowly cooled at 380 oC - 420 oC to control the transformation form the austenite to acicular ferrite and bainite， which can obtain excellent mechanical properties. A mathematical model is established for the stacking process of 80 mm extra- thick plates of EH420 marine steel， and the accuracy of the model was verified by actual temperature measurement. The influence of stacking parameters on the residence time of extra-thick plates of marine steel in the transformation zone is studied.It is found that the temperature of the surface layer of plate stacking gradually decreases， while the decrease rate of temperature in the middle and bottom of the stacking are significantly lower. The stacking rate has little effect on the cooling rate， while the initial temperature of the plate has a great impact on the cooling rate. With the initial temperature of the extra-thick plates stacking increasing from 400 oC to 500 oC， the residence time of the stacking center in the phase transformation zone decreases from 35.6 h to 15.1 h. As the height of extra-thick plates stacking increases， the time required for cooling time rises. When the stacking height increases from 2.0 m to 3.0 m， the residence time in the structure transformation zone in the middle of the stacking increases from 17.1 h to 20.8 h， which is caused by the decrease of the stacking surface and the cooling rate.关键词：Extra-thick Plates;Stack;Slow Cooling;Numerical Simulation14|6|0更新时间：2025-09-11
- 摘要：The high alloying degree of GH4151 nickel-based superalloy leads to cracks and crystal mixing defects in the billet process， which significantly reduces the material utilization rate. Meanwhile， the grain size of GH4151 is more sensitive to the temperature and time of solid solution treatment. Using vacuum induction smelting （VIM） + electric slag remelting （ESR） + vacuum arc remelting （VAR） triple smelting GH4151 ingot， after homogenization billet preparation into
- 摘要：The upsetting and thickening of the pipe-end of the drill pipe is a very important process in the production process of the drill pipe. After upsetting at the pipe-end， the wall thickness of pipe body and pipe-end are different， which will cause the mechanical property deviation of pipe body and pipe-end during quench and temper heat treatment. This leads to large differences in the yield strength， impact toughness， hardness and grain size of the material， which is not conducive to the safe operation of high strength and high toughness drill pipe. Tianjin Pipe Corporation has developed secondary Q&T procedure， by 900 ℃for 30 min quenching + 650 ℃ for 60 min tempering + 900 ℃ for 30 min quenching + 650 ℃ for 60 min tempering to fully refine the grain size， improve the strength and toughness， and reduce the uniformity of pipe body and pipe-end .Final the yield strength of both pipe body and pipe-end are 1 140 MPa-1 300 MPa， tensile strength beyond 1 200 MPa. The CVN at -20 ℃ impact energy reached to 100 J for longitudinal pipe body and 80 J for longitudinal upset end at room temperature. The excellent strength and toughness character， and the uniform property of pipe body and upset assures the drill pipe can be used safelyIt provides good material performance guarantee for the safety of ultra-high strength and high toughness drill pipe in the ultra-deep wells which more than 9 000 meters.关键词：165ksi;Steel Pipe;Drill Pipe;Pipe-end Upsetting;High Strength;High Toughness15|4|0更新时间：2025-09-11
- 摘要：Mechanical properties， microstructure and fracture behavior of Fe-27Mn-9 Al-1C-0.25V low-density steel were analyzed after different heat treatment temperature.The results show that with the increased of heat treatment temperature from 700 ℃ to 1 000 ℃， the yield strength and tensile strength of the experimental steel decreased continuously， while the elongation increased continuously.When the heat treatment temperature reached 900 ℃， the plasticity of experimental steel was significantly improved. The experimental steel heat treated at 1 000 ℃， the product of strength with ductility reached the highest ， its tensile strength reached 960 MPa， total elongation was 46%， and product of strength with ductility reached 44.16 GPa·%. Through microstructure of samples at different heat treatment temperatures， it was found that when the heat treatment temperature was ≤800 ℃， a distinct precipitate phase can be observed at the austenite-ferrite interface， identified as κ-type carbides. The κ-type carbides at the interphase can cause crack initiation， leading to a significant reduction in the toughness and ductility of the test steel.关键词：Low Density Steel;Heat Treatment Temperature;Mechanical Properties;Microstructure4|2|0更新时间：2025-09-11
- 摘要：Solution treatment temperature is a critical factor in regulating the precipitate and grain structure of superalloys. In this study， different solution treatment temperatures were applied to investigate the grain structure and the primary γ′ phase of a novel deformed nickel-based superalloy GH4251. The effects of solution treatment temperature on the microstructure were analyzed using multi-scale characterization analysis. The results show that both grain size and the volume fraction of primary γ′ phase decrease significantly with increasing solution treatment temperature. Particularly at the over-solid solution temperature， the primary γ′ phase is nearly entirely dissolved， causing the grain boundaries to lose their pinning force， which results in grain coarsening and a significant decrease in tensile strength and ductility. The increase in grain size is the primary cause of the reduced room-temperature tensile properties of the alloy. Statistical analysis of the equivalent particle radius （r） and volume fraction （f） of the primary γ′ phase in GH4251 was conducted， and data fitting was used to establish the relationship between these two parameters and the average grain size. The dissolution behavior of the primary γ′ phase in GH4251 alloy was analyzed from the perspective of atomic diffusion. It was observed that the γ′/γ interface of the primary γ′ phase exhibited enrichment of Cr and Co alongside depletion of Al， Ti， and Ta. Under the combined influence of solute element enrichment and the elastic stress field， the edges of the primary γ′ phase protruded， gradually detaching to form smaller γ′ particles. The elevated solid solution temperature accelerated this process， ultimately leading to the complete dissolution of the primary γ′ phase.关键词：GH4215 Alloy;Primary γ′ Phase;Grain;Solution Treatment21|5|0更新时间：2025-09-11
- 摘要：In order to reveal the change and reason of microstructure and hardness of antimony micro-alloyed ferrite cryogenic steel during continuous cooling transformation， hot compression tests were conducted on a Gleeble 3800 thermal simulator and the dynamic continuous cooling transformation （CCT） curves of the experiment steel were determined based on the experiments. The microstructure and the Vickers hardness at different cooling rates was characterized by optical microscope and microhardness tester， respectively.The results show that when the cooling speed remains at 0.1 ℃ / s， the microscopic organization of experimental steel is composed of polygonal ferrite and beads； when the cooling speed is within 0.3 ℃-1 ℃ / s， the microstructure appears as polygonal ferrite， pearlosite and granular bainite； When the cooling speed is increased to 3 ℃/ s，-40 ℃/ s， the microstructure appears as polygonal ferrite and plated bainite. Due to fine grain and granular bainite strengthening， the hardness increases rapidly from 172.1HV to 207.7HV when the cooling rate is 0.1 ℃/s-1 ℃/s. Due to the refinement of the microstructure and the increase of the proportion of plated bainite， when the cooling rate is 3 ℃/s-40 ℃/s， the hardness increases linearly from 214.9 HV to 261.8 HV with the cooling rate. The suitable controlled cooling interval of Sb-alloyed ferritic cryogenic steel is 3 ℃/s-40 ℃/s.关键词：Ferritic Cryogenic Steel;Antimony Micro-alloyed;Dynamic CCT curve;Microstructure;Hardness3|1|0更新时间：2025-09-11
Forming and Phase Transition
- 摘要：The yield to tensile strength ratio is the important performance index of seamless steel tube for high strength structures. Studied the change law of mechanical properties of S770QL steel （mass fraction） /%： 0.15C，0.28Si，1.30Mn，0.009P，0.003S，0.20Cr，0.02Ni，0.47Mo，0.025Al，0.08V，after different quenching and tempering processes above Ac3， and and the microstructure was analysed.The results show that after the quenching temperature of the steel pipe from 880 ℃ to 940 ℃， the grain size of austenite grain is relatively small， not exceeding 20 μm ， and all the microstructure are transformed into martensite. With the increase of the quenching temperature， the average grain size of austenite gradually increases. Under the condition of the same tempering process， the bending strength ratio decreases with the increase of the quenching temperature. After high temperature tempering， all the microstrucute are transformed into tempering chordite. With the increase of tempering temperature， under the combined action of precipitation enhancement and fine crystal reinforcement， the bending strength ratio increases first， and decreases again after the tempering temperature exceeds 660 ℃. In comprehensive consideration， 920 ℃ 60 min quenching （water cooling） + 600 ℃ -630 ℃ 120 min tempering （air cooling） process is adopted， and the yield strength ratio of steel pipe can be maintained between 0.89 and 0.90， and the comprehensive performance is optimal.关键词：Yield to Tensile Strength Ratio;Quenching;Tempering;Seamless Tube11|4|0更新时间：2025-09-11
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Effect of Cold Rolling and Annealing Process on the Thermal Expansion Properties of Ni36 Invar Alloy
摘要：The effects of cold rolling and annealing process on the microstructure and thermal expansion properties of Ni36 Invar alloy were studied in this work. The results show that the coefficient of thermal expansion （ abbreviated as CTE） is greatly reduced by the cold rolling treatment with a depression rate of 30%-75%. The average CTE i.e.，
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