最新刊期
卷 41 ， 期 4 ， 2020
- 摘要：The quenching process of H380 grade heat-treated steel rails is analyzed by computer numerical simulation. The rail heat treatment process is a " continuous isothermal transformation process" between the isothermal transition and the continuous cooling transition. The calculation shows that the temperature drop of the H380 grade heat treatment steel rail is controlled at 200 ~ 250 °C , and the rail head phase transition temperature should not exceed 620°C , the pearlite structure phase transition temperature at the tensile strength sampling position at the rail head should not exceed 650°C, and the phase change incubation period is between 22 〜30 s. In this section, the cooling intensity is strengthened and the pearlite phase transition temperature is lowered. It is beneficial to the deepening of the hardened layer of the rail head, to increase tensile strength of the heat-treated rail of this grade.关键词：H380级别钢轨;钢轨热处理;数值模拟;力学性能2|0|0更新时间：2026-01-21
- 摘要：Nail-shooting technique is applied to measure shell thickness of typical high-carbon chromium bearing steel GCrl5 240 mm x240 mm casting bloom, and the electromagnetic stirring position at different casting speed is calculated by the solidification law which can determine the length of the liquid core and the solidification coefficient according to the solidification rate 0. 65 and 0.75. Meanwhile, compared with the calculation results of the secondary model of the casting machine, the influence of the casting speed on the quality of the continuous casting bloom is discussed without changing the position of final electromagnetic stirring (9.4 m). And the magnetic stirring strength of the final electromagnetic stirring is measured by using the tesla meter HT201 to determine the optimal process parameters of final electromagnetic stirring. The results show that increased pulling speed from 0. 68 m/min to 0. 75 m/min has better effect； the optimized electric stirring parameters are current 450 A and frequency 8 Hz ； after process improved, the qualified rate of central segregation is increased from original 75% to 92%.2|0|0更新时间：2026-01-21
- 摘要：The law of increasing nitrogen by RH withdrawing pump and the effect of nitrogen content on inclusions in ultra-low carbon enamel steel are studied. The results show that the time of increasing nitrogen by RH withdrawing pump ≤ 25 min, the relationship between the time of withdrawing pump and the nitrogen content in steel is basically in accordance with a quadratic formula γ = -0. 226 x2+ 9.429 x +31.21. The inclusions in enamel steel are mainly the second phase precipitates containing Ti and a small amount of Al203particles. The main composition of small inclusions is TixS, and that of large inclusions is TiN. The nitrogen content of conventional enamel steel is 0.003 8% , and the nitrogen content of two nitrogen increased enamel steel is 0.010 8% and 0. 012 7%. The total inclusions in the corresponding steel are 355. 61, 545. 74 and 558. 77μm2/mm2respectively. The number of inclusions in each size range in conventional enamel steel is the least. Considering hydrogen storage property and RH nitrogen increasing time of enamel steel, the nitrogen content in steel is suitably controlled around 0. 01% .2|0|0更新时间：2026-01-21
- 摘要：The production process of tested spring steel 60Si2Mn(/% ：0.58C, 1.75Si,0.75Mn,0.012P,0.005S, 0.006Als ,0.008Alt)is not adding aluminum cake but adding ferrosilicon to deoxidize in an 100 t converter, controlling end [C]≥0.08% ,and tapping liquid temperature 1620 〜1660℃,LF original temperature ≥ 1500℃ ,refining time no less than 35 min,RH vacuum ≤100 Pa for，20 min,feeding 100 meters of calcium and silicon wire for modification of inclusions before soft blowing, in whole process shielding-atmosphere casting 150 nun square billet. Analysis results show that the oxygen content in steel reaches the lowest in RH refining process, and rises in tundish stage. In LF refining process, the nitrogen increase of liquid steel is obvious. Inclusions are mainly composed of A12O3 ,SiO2 ,MgO and CaO. During LF refining, the content of SiO2decreases to 26.7% , while the content of MgO and CaO increases to 36.7%. Finally, the inclusions in the casting billet are 33% Al2O320.7% SiO2and 45% MgO and CaO to decrease the high hardness inclusions in steel.2|0|0更新时间：2026-01-21
- 摘要：According to the effect of C, Mn, V, N and Ti in non-quenched-tempered microalloyed steel, the chemical composition of non-quenched-tempered steel N80 oil casing tube is designed. Based on lab furnace normalizing test data, the on-line normalizing rolling process parameters are determined. The microstructure of the non-quenched and tempered N80 steel 139.7 mm x9.17 mm oil casing tube is ferrite + pearlite with the yield strength 575 ~638 MPa, tensile strength 789 ~840 MPa, elongation 21% -23% and 3/4 size impact energy at 0℃ being 39 ~87 J fully to meet the requirements of API Spec 5CT (10th Edition ,2018).3|0|0更新时间：2026-01-21
- 摘要：The carbon content of low carbon free-cutting stainless steels such as 430F and 430FR is ≤0.035%. Because Xingtai Steel adopts the 60 t AOD-LF-CC low-cost production process, it is by using expensive low-carbon alloys and increasing terminal decarburization time to ensure product carbon qualified rate. Compared with the same series of low-carbon 430 ferritic stainless steel, the cost per ton of steel rises by 100 yuan. By increasing AOD liquid decarburization temperature and adjusting process basicity to realize tapping [C]≤0.015%. In the tapping and refining process, the magnesia-calcium slag line ladle is used to replace the magnesium-carbon slag line ladle, and the oxidizability of the refined slag is adjusted to achieve an average carbon increase of ≤0.007% in the refining process, and the qualified rate of the carbon content of the low-carbon free-cutting stainless steel is increased from 76% to over 92% , to realize the continuously produces low carbon 430 series free cutting stainless steel by AOD-LF-CC process.2|0|0更新时间：2026-01-21
- 摘要：Effect of quenched and tempered treatment, normalizing & quenched and tempered treatment on micro¬structure and properties of 42CrMo forging crankshaft steel is studied by means of metallographic microscope observation and mechanical performance analysis. The results show that after the quenching and tempering treatment ( 860 ℃ quenched + 580℃ tempered) , the base structure for the forging crankshaft billet is temped sorbite and much amount of white ferrite with coarse grain non-homogeneously distributed at the central area of crankshaft. Its mechanical properties are TS 997 ~ 1211 MPa, YS 990 〜1204 MPa, el. 11% ~ 13% , RA 40% -48% , and impact energy 72 ~92 J. On the contrary,with a normalizing pretreatment(880℃ air cooling) before the quenching and tempering treatment process, the microstructure for the 42CrMo forging crankshaft steel become more uniform, its mechanical properties are TS 1100 〜1220 MPa, YS 1107 ~ 1188 MPa, el. 13% ~ 15% , RA 50% ~56% and impact energy 83 ~91 J. Therefore, the normalizing pretreatment at 880 °C air quenching at 860 °C and high temperature tempering treatment at 580 T is the optimized heat treatment process for the 42CrMo forging crankshaft steel.关键词：42CrM钢;锻造曲轴;调质处理;正火预处理组;织性能2|0|0更新时间：2026-01-21
- 摘要：The effects of process and different calcium treatment methods on Ca/S and inclusions in steel and the effects of low superheat match and dynamic soft reduction technology on macrostructure quality of billets of acid resistant steel Q345R smelting by “BOF-LF-RH-CC" process are analyzed. Research shows that"LF + RH + calcium treatments" process can significantly increase the Ca/S in molten steel and reduce the size of A and B inclusions in steel. As calcium treatment is carried out after RH breaking vacuum, the class 2. 0 Ds inclusions appear in finished plate, but the size and quantity of these inclusions can be reduced by prolonging the soft blowing time. With LF/RH two steps calcium treatments process and soft blowing time for 16 ~20 min after RH calcium treatments, the inclusion size of B, Ds, D can be controlled ≤1.0 rating and the inclusion size of A,C can be controlled ≤0.5 rating in steel plates. Core segregation of billet macrostructure rating is C type 1.0 by 5 〜12℃ superheat casting match and dynamic soft reduction technology, the segregation rating of each elements is low. Using the process, the composition, inclusions and macrostructure quality can meet the acid resistant steel Q345R requirements.2|0|0更新时间：2026-01-21
- 摘要：The surface scabs of 1028 cold heading steel wire rod are analyzed by metallurgy and scanning electron microscope. It is concluded that the main reason is the high nitrogen content (0. 0133% ) in the steel, the Ti in steel (0.033% ) is not enough to completely fix nitrogen, and the excess N with B formes BN precipitates to weaken the grain boundary and form microcracks led to the surface cracking of the billet and finally inherited to wire rod surface after rolling. By reducing the scrap ratio from 21% to 10% and the deoxidization intensity of tapping, adding ferroboron after feeding Ti- Fe wire for 5 min after white slag, controlling the soft blowing volume of LF, and aluminum loss≤0.003% during casting process, N is stably controlled within 60 x 10-6to ensure Ti/≥4the defective rate of surface scabbing is reduced from original 60% to less than 1. 0% .关键词：10B28钢, 冷镦钢线材;表面结疤;成因分析;改进工艺2|0|0更新时间：2026-01-21
- 摘要：For improving the problem of non-metallic inclusions in low carbon aluminum killed steel produced by CSP process at Jiuquan steel Co,with sampling at each phase of steelmaking and continuous casting,the study of inclusions in steel is carried out by metallographic analysis, electron probe and scanning electron microscopy. The results show that under the current process conditions,the casting slab T[0] is more than 30 x 10-6by BOF blowing N2/Ar exchange process,LF soft blowing 36 min and lable heel 2% ~4% ,the 2μm inclusions ≥66% and spherical inclusions ≥94% ,and the type of inclusions is mainly calcium aluminate plus a certain amount of CaS. After the process optimization, all indexes meet the requirements of DQ deep drawing steel production.2|0|0更新时间：2026-01-21
- 摘要：The production process and actual product performances of ASTM A 387M Gr. 11 CL2 steel 24 mm plate for pressure vessels produced by Chongqing Iron and Steel Co Ltd are introduced. The rolling process and heat treatment of test steel (/% ：0.13C,0.56Si,0.56Mn,0.036Alt,0.005P,0.001S,l.02Cr,0.50Mo)300 mm x2010 mm casting slab are rough rolling at >1000 °C , thicknees of middle bloom 72 mm, finishing rolling at 880 ~ 940 °C , end finish rolling at 850 ~870 °C,laminar cooling to 690 -710 °C , air cooling to room temperature and normalizing at 890 〜910 °C, tempering at 650 ~ 670 °C. Practice shows that the performance indexes of the steel meet the technical requirements and the steel has good impact toughness at low temperature, i. e. the impact energy of test steel at -40°C is 149 ~ 172 J.2|0|0更新时间：2026-01-21
- 摘要：According to the requirements of SY/T 6952.2-2013 standard and working conditions of heavy oil thermal recovery wells, Daye Special Steel Co Ltd successfully produces a kind of grade 110SH-1 thermal recovery casing with high strength and toughness by using 0.9 ~ 1.2Cr-0.3 ~ 0.6 Mo-based low alloy + Nb-Ti-V respectively 0. 01 〜0. 05 composition design of microalloy to reduce the use of precious alloy and production cost. The Φ 177.8 mmx 9.19 mm seamless steel pipe is produced by process of "70 t EAF →LF + VDC→CM Φ230 mm bloom →CPE mill rolling→quenching and tempering heat treatment" , according to the test results it is defined that the quenching temperature 920 ℃, water cooling, tempering temperature 660℃ ,air cooling process. The results show that the conventional performance, high-temperature anticreep performance, full-size blasting, full-size crushing and other test results of the steel grade thermal recovery casing fully meet the requirements of SY/T 6952. 2-2013 industry standard.3|0|0更新时间：2026-01-21
- 摘要：The effects of cold deformation (0% - 80% ) and 1000 ~ 1090 °C solid sulution treatment on the microstructure and magnetic properties of 0Crl8Nil2 and 0Crl6Nil4 austenitic stainless steels are discussed based on composition and structure stability. The results show that the austenite stability of stainless steel 0Crl8Nil2 and 0Crl6Nil4 is better than that of SUS304, and 0Crl6Nil4 is the best. Deformed martensite is formed during cold rolling deformation of stainless steel 0Crl8Nil2 and 0Crl6Nil4. The relative permeability of 0Crl6Nil4 during cold rolling is always below 1.010, the proportion of deformed martensite of 0Crl8Nil2 is up to 3.5% , and the relative permeability is increased to 1.353. After solution heat treatment, the relative permeability can be controlled below 1.010. Combined with the field production conditions, the heat treatment process of two kinds of austenitic stainless steels is solid solution treatment at 1060 °C for 80 s per mm.2|0|0更新时间：2026-01-21
- 摘要：The exist style of niobium in 0.25% Si non-oriented silicon steel and the interaction mechanism, and the effect of Nb on microstructure and electromagnetic properties in the finished steel are studied. The results show that, for present work, the solution and precipitation of the niobium inclusions and the traditional inclusions can be improved by adding 0.008 3% niobium into the liquid steel. Thus, the average size of inclusions will obviously decrease from 152 nm to 64 nm,and the number of which will sharply increase from 1.7 x 107/mm3to 8.4 X 107/mm3. Among of which,the main niobium contained is Nb (C,N) ,with size being hundreds of nanometer grades. They can pin the grain boundary and decrease the diffusion rate of grain boundary significantly, and then resulting the occurrence of the refinement grain size segregating and the island shape grains. Finally,the iron loss and magnetic induction of the finished steel are obviously deteriorated by 0.7 W/kg and 0. 03T,respectively. More over, the deterioration of iron loss and magnetic induction in steel will increase monotonically with increasing niobium content. The Nb inclusions lead to increase of iron loss P15/50by deterioration of hysteresis loss.2|0|0更新时间：2026-01-21
- 摘要：In order to investigate the negative temperature impact properties of 14Cr1MoR steel extra thick plates, the negative temperature impact tests at 0~-30℃,for 136 mm thick 14Cr1MoR steel plates produced by a steel plant with delivery ( normalizing + tempering) and max PWHT state are carrued out,and by metallographic microscope, the full thickness structure, grain size and inclusions in steel with delivery and max PWHT state are analyzed. The results show that the ultimate impact temperature of 14Cr1 MoR steel extra thick plate is -30°C,the -30 °C impact energy at 1/2 plate thickness with delivery and max PWHT state are respectively 150 ~ 173 J and 19. 5 ~ 97 J. The metallographic structure study shows that the main reason that affects the negative temperature impact performance of steel plate after max. PWHT is the carbides aggregate and grow up in the grain and grain boundary, and tend to spheroidize, which weakens the toughness of matrix and the properties of grain boundary, thus resulting in a significant decrease in impact energy.2|0|0更新时间：2026-01-21
- 摘要：Analysis of phase composition, particle size and hardness of metallographic structure and sulfide inclusions in 1215MS free cutting steel Φ12 mm coil are carried out by means of optical microscope, scanning electron microscope with energy dispersive spectrometer, microhardness tester and thermdynamic software Thermo-Calc. The results show that, the proportion of ferrite in 1215MS steel is 93% -96% ,and the proportion of pearlite is 4% ~5% ; the average equivalent diameter of ferrite is 22.30 μm,the average diameter of pearlite is 16. 83 p.m, sulfide is evenly distributed in the edge of grain boundary and the ferrite,the equivalent diameter of sulfide is 5.077μm, the average Vickers hardness of MnS, ferrite, and pearlite is 80 HV10,100 HV10,175 HV10,respectively.2|0|0更新时间：2026-01-21
- 摘要：By measuring the dilatometric curves of Nb-Ti-V micro-alloying 0.04 ~ 0.08C-0. 6 ~ 1.2Ni-0.1 ~ 0. 5Cr- 0.1 ~0.5Cu crack-resistant steel EH47 for large container ship with cooling rate of 0. 05 ~50 ℃/s on a Gleeble-3800 thermomechanical simulator, and combining with metallographic analysis, a CCT diagram of austenite continuous cooling transformation is obtained. And the microstructure and hardness of the continuous cooling transformation occurring in EH47 crack-resistant steel are investigated. The results show that the microstructure of EH47 crack-resistant steel at 0. 05 〜 50 ℃/s cooling rate consists of ferrite + pearlite and accicular ferrite + bainite. Even the cooling rate as high as 50℃/s, no martensite occurs in the microstructure.2|0|0更新时间：2026-01-21
- 摘要：The effects of boron contents on the solution time and temperature of precipitated phase in steel S31254 are studied by solution treatment. The time and temperature required for the complete solution of steel S31254 second phase under different boron contents are obtained. The results show that as the boron content increases, the required solid solution temperature and time decrease. When the boron content in the steel is 0.002% ,a relatively pure austenite structure can be obtained by solid solution treatment at 1200℃ for 4 hours, that is to say, the second phases precipitated in the grains and grain boundary have been re-dissolved into the matrix during the hot working process. In addition, during the solid solution treatment, the second phases in the grains preferentially dissolve, and as passage of time, the second phases at the grain boundary gradually dissolve.2|0|0更新时间：2026-01-21
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