60Si2Mn 钢高温变形抗力的热模拟实验测定

利用Ｇｌｅｅｂｌｅ－２０００热模拟试验机模拟测定了６０Ｓｉ２Ｍｎ、６０Ｓｉ、４０Ｃｒ及２０Ｍ等钢种的在高温下变地的真应力一真应变曲线,讨论了高温变形抗力与变形温度及形变量之间的关系,结果表明：高温变形抗力与变形温度及形变量有很大关系,变形抗力随主为形温度的升高而降低,同时认为６０Ｓｉ２Ｍｎ钢不会在马钢热轧生产中赞成对轧辊等设备及传动系统的损伤。     

热轧材60Si2Cr AΦ13 mm弹簧钢硬度奇高原因分析

通过硬度试验、金相检验及模拟试验，统计分析了同期生产的不同批号60Si2CrA Φ13mm弹簧钢的化学成分差异，找出了其中一个批号的热轧材60Si2CrA Φ13mm弹簧钢硬度奇高的主要原因是其化学成分中Mn，Cr两大合金元素含量偏高。     

热轧贝茵体钢板的抗张性能

0. 1％C—2％Mn—Cu—Ni—Cr—Mo和0. 07％C—2. 2％Mn—Cr—Mo钢在模拟热带钢轧机低温卷取的控制条件下,热轧后组织为细贝茵体,抗张强度达60～80公斤/毫米~2,并具有良好的抗弯能力和韧性。本文研究了化学成分Si和Mo以及热轧条件的影响,并对显微组织和非金属夹杂的影响也作了讨论。     

60Si2Mn弹簧钢相变规律研究

目的:基于热模拟试验机对60Si2Mn弹簧钢相变规律研究。方法:采用改变外界施加压力观察60Si2Mn弹簧钢试件自身应力大小的改变,并测定外界施加压力与试件自身应力的线性关系。结果:当外界施加压力持续增加时,60Si2Mn弹簧钢会产生三种不同的应力状态。结论:当外界施加压力小于273.8N时,撤消压力60Si2Mn弹簧钢试件可恢复形变;当外界施加压力等于273.8N时,撤消压力60Si2Mn弹簧钢试件形变不会恢复;当外界施加压力大于273.8N时,60Si2Mn弹簧钢试件出现断裂。     

60Si2Mn弹簧钢相变规律研究

目的:基于热模拟试验机对60Si2Mn弹簧钢相变规律研究。方法:采用改变外界施加压力观察60Si2Mn弹簧钢试件自身应力大小的改变,并测定外界施加压力与试件自身应力的线性关系。结果:当外界施加压力持续增加时,60Si2Mn弹簧钢会产生三种不同的应力状态。结论:当外界施加压力小于273.8N时,撤消压力60Si2Mn弹簧钢试件可恢复形变;当外界施加压力等于273.8N时,撤消压力60Si2Mn弹簧钢试件形变不会恢复;当外界施加压力大于273.8N时,60Si2Mn弹簧钢试件出现断裂。     

60Si2Mn弹簧钢端部裂纹产生原因分析及探讨

分析了在生产实践中,60Si2Mn弹簧钢热轧圆钢出现端部裂纹缺陷的原因,及解决该缺陷的方法探讨和工艺调整.     

淮钢开发出两新产品

淮钢HRB400热轧带肋钢筋(20MnSiV)及60Si2Mn热轧弹簧圆钢双获江苏省高新技术产品认定证书。 淮钢非常重视产品创新工作,为满足国内市场的需要不断加大新产品开发的力度。HRB400热轧带肋钢筋就是该公司为满足各种大型建筑和高层建筑的需要,利用微合金化技术开发生产出的省级新产品。60Si2Mn热轧弹簧钢是该公司针对我国汽车工业的发展及铁路提速的需要而开发的新产品。     

小方坯连铸机电磁搅拌工艺参数优化实践

介绍了石钢转炉炼钢厂2#小方坯连铸机新上结晶器电磁搅拌的生产工艺,通过不断地摸索实践及优化,提出了适合20G,45#,40Cr,60Si2Mn钢小方坯钢种质量要求的电磁搅拌参数,满足了石钢的钢种开发生产及对产品质量需要。     

攀钢钢种性能特点及其发展方向

本文综述了攀钢在试验和生产钒钛钢种中钢材的性能特点、变化及与攀枝花资源条件的关系。 文中对攀钢生产的重轨钢、氧气瓶钢、硅钢、工业纯铁、抗H_2S腐蚀石油套管钢、AD_3及09V低合金钢等的综合性能作了概述。生产实践表明:攀钢的某些钢种与国内同类型钢种比较,具有强度高、磁性和抗H_2S腐蚀性能较好、不易出现白点缺陷等特点。此外,对攀钢钢种发展方向,提出应着重研究和发展以残余V、Ti为基础的 Mn—V、Mn—Ti、Mn—Ti—B、Mn—V—Si和Mn—Si一Ti等低合金高强度钢系列及满足特殊用途的专用钢种。     

50Mn2V钢工艺适应性研究

对50Mn2V钢的工艺适应性进行研究,通过抗压热模拟试验分析50Mn2V钢对生产设备的要求,并与高强度钢种3Cr2Mo和DB785进行对比;通过热塑性试验探讨50Mn2V钢的高温热塑性.试验结果表明,武钢现有的设备完全有能力生产高强度的50Mn2V钢.     

Gigacycle Fatigue Behavior of 1800 MPa Grade High Strength Spring Steel for Automobile Lightweight

Gigacycle fatigue behavior of 60Si2CrVA high strength spring steel was investigated by ultrasonic fatigue test machine. Fatigue fractography was observed by scanning electron microscopy （SEM）. Maximum inclusion sizes and fatigue strength in different volumes were estimated by statistics of extreme values （SEV） and generalized Pareto distribution （GPD） methods. The results showed that S N curves of 60Si2CrVA spring steels for two rolling processes were not horizontal asymptotes but a gradient in a regime of 109 cycles, and traditional fatigue limits were eliminated. Surface machined topography and inclusions in steel were major factors that led to elimination of fatigue limit for 60Si2CrVA spring steel. The SEV and GPD methods could effectively predict size of the maximum inclusion and fatigue strength in different volumes of 60Si2CrVA spring steel. Predicted fatigue strength was in accordance with experimental results by ultrasonic fatigue testing.     

60Si2Mn钢动态再结晶数学模型的实验研究

利用计算机技术对轧制过程进行组织性能预报在工业生产中有着广泛的应用前景，而开发合理的数学模型就成为组织性能预报的关键：轧制过程中发生的动态再结晶行为直接影响着预报结果的可靠性。作者在实验室条件下采用单、双道次压缩实验对60Si2Mn钢的轧制过程进行了研究，得到了该钢种动态再结晶的计算模型：     

新型高强韧性弹簧钢40T 和44T 脱碳倾向的研究

新型高强韧性弹簧钢40T(%:0.41C-2. 12Si- 1.03Cr- 1.98Ni-0.31Mo-0.25V),44T(%:0.44C-2.28Si- 1.42Cr-0.25V)和弹簧钢60Si2CrVA(%:0.59C-1.65Si-1.11Cr-0.18V)的φ18 mm 和φ26 mm 试验钢材由北满特钢 20t电弧炉冶炼,经轧制、冷拔而成。各钢材经860～1000℃加热脱碳试验的结果表明,40T钢碳含量较低,并 有～2%Ni,其脱碳倾向明显低于44T钢和60Si2CrVA钢;880 ℃加热1 h时,40T钢没有脱碳,44T钢脱碳层深 0.05mm,60Si2CrVA钢脱碳层深0.15 mm;1000 ℃加热20 min,40T钢脱碳层深0.1 mm,44T 钢0.2 mm, 60Si2CrVA钢0.4 mm。40T钢脱碳倾向小,有利于提高弹簧的疲劳寿命。     

微合金化非调质钢C38N2动态再结晶行为

针对微合金化非调质钢热轧过程的变形特征,通过Gleeble-3800热模拟试验机研究了Nb-Ti-V非调质钢C38N2(/%:0.40C、0.52Si、1.42Mn、0.010P、0.047S、0.028V、0.025 Ti、0.022Nb)在950～1 150℃,变形速率0.1～10 s-1变形量60%,单道次压缩时的奥氏体动态再结晶过程,计算得出C38N2钢的动态再结晶晶粒尺寸模型和动态再结晶状态图。结果表明,C38N2钢变形温度越高,变形速率越低,则发生动态再结晶的储蓄能越小,动态再结晶越易发生。C38N2钢的动态再结晶激活能Q_d=294.905 kJ/mol。     

Forming response of retained austenite in a C‐Si‐Mn high strength TRIP sheet steel

TRIP sheet steels typically consist of ferrite, bainite, retained austenite, and martensite. The retained austenite is of particular importance because its deformation‐induced transformation to martensite contributes to excellent combinations of strength and ductility. While information is available regarding austenite response in uniaxial tension, less information is available for TRIP steels with respect to the forming response of retained austenite in complex strain states. Therefore, the purpose of this work was to study the austenite transformation behaviour in different strain paths by determining the amount of retained austenite before and after forming. Forming experiments were performed on a high strength 0.19C‐1.63Si‐1.59Mn TRIP sheet steel 1.2 mm in thickness in two different strain conditions, uniaxial tension (ε₁ = ‐2ε₂) and balanced biaxial stretching (ε₁ = ε₂). Specimens were formed to strains ranging from zero to approximately 0.2 effective (von Mises) strain. Specimens were tested both longitudinally and transverse to the rolling direction in uniaxial tension, and subtle mechanical property differences were found. The volume fraction of austenite, determined with X‐ray diffraction subsequent to forming, was found to decrease with increasing strain for both forming modes. Some modification in the crystallographic texture of the ferrite was observed with increasing strain, in specimens tested in the balanced biaxial stretch condition. This trend was not evident in the uniaxial tensile test results. Slight differences were found in the transformation behaviour of the austenite when formed in different strain conditions. More austenite transformed in specimens tested parallel to the rolling direction than transverse to the rolling direction in uniaxial tension. The amount of austenite transformed during biaxial stretching was determined to be greater than the amount transformed in uniaxial tension for specimens tested transverse to the rolling direction at an equivalent von Mises strain. The amount of austenite that transformed in biaxial tension, however, was comparable to the amount of austenite that transformed in specimens tested longitudinal to the rolling direction in uniaxial tension.     

Mathematical modeling of the hot strip rolling of microalloyed Nb, multiply-alloyed Cr-Mo, and plain C-Mn steels

Industrial mill logs from seven different hot strip mills (HSMs) were analyzed in order to calculate the mean flow stresses (MFSs) developed in each stand. The schedules were typical of the processing of microalloyed Nb, multiply-alloyed Cr-Mo, and plain C-Mn steels. The calculations, based on the Sims analysis, take into account work roll flattening, redundant strain, and the forward slip ratio. The measured stresses are then compared to the predictions of a model based on an improved Misaka MFS equation, in which solute effects, strain accumulation, and the kinetics of static recrystallization (SRX) and metadynamic recrystallization (MDRX) are fully accounted for. Good agreement between the measured and predicted MFSs is obtained over the whole range of rolling temperatures. The evolution of grain size and the fractional softening are also predicted by the model during all stages of strip rolling. Special attention was paid to the Nb steels, in which the occurrence of Nb(C, N) precipitation strongly influences the rolling behavior, preventing softening between passes. The present study leads to the conclusion that Mn addition retards the strain-induced precipitation of Nb; by contrast, Si addition has an accelerating effect. The critical strain for the onset of dynamic recrystallization (DRX) in Nb steels is derived, and it is shown that the critical strain/peak strain ratio decreases with increasing Nb content; furthermore, Mn and Si have marginal but opposite effects. It is demonstrated that DRX followed by MDRX occurs under most conditions of hot strip rolling; during the initial passes, it is due to high strains, low strain rates, and high temperatures, and, in the final passes, it is a consequence of strain accumulation.     

U75V重轨钢BD2开坯过程有限元数值模拟和分析

通过ANSYS/LS-DYNA非线性有限元软件对重轨钢U75V(/%:0.70～0.78C、0.50～0.70Si、0.75～1.05Mn、≤0.025P、0.008～0.025S、0.04～0.08V)在BD2轧机于1 200℃开坯5道次轧制过程进行了数值模拟,分析了各道次稳定断面处等效应力、等效应变的分布情况。结果表明,轧件头部、腰部和底部随每道次的变化其应力、应变分布存在差异;稳定截面处轨头、轨腰和轨底各道次应力曲线的分析得出,轨头应力变化最大,最大值达64.8 MPa,提高重轨轨头的屈服强度有利于延长重轨寿命。     

弹簧扣件用60Si2Mn热轧盘条的开发及应用

介绍了安钢60Si2Mn热轧盘条的工艺特点、产品质量,及其在铁路弹簧扣件生产中的应用。冶炼工艺采取了多项关键技术以实现窄成分控制和钢水洁净度控制,保证了铸坯无缺陷生产;利用摩根第六代高速线材生产工艺设备,采用控轧控冷,盘条尺寸精确控制在13～13.2mm,抗拉强度为950～1050MPa,面缩为36%～47%,硬度为269～288HRB,组织为S+P+F,脱碳层深度小于1%D;生产的60Si2Mn弹条硬度为41～46HRC,组织为均匀回火索氏体,疲劳试验达到700万次无损坏,残余变形小于1mm,完全满足TB/T 1495.2和用户要求。     

60Si2MnA弹簧钢盘条脱碳层控制工艺的优化

60Si2MnA弹簧钢ø9ø12 mm盘条的生产流程为100 t BOF-LF-VD-150 mm×150 mm坯连铸-高速线材轧制工艺。讨论了脱碳机理和分析了脱碳的影响因素。通过适当降低二加热段温度,提高均热段温度,铸坯总加热时间由2.7 h降至1.5 h,控制加热炉内氧含量3%5%,开轧和吐丝温度分别从（1000±20）℃和（850±15）℃降至（950±20）℃和（820±20）℃,减少727℃以上温度的风冷时间等工艺措施,使60Si2MnA弹簧钢盘条的全脱碳层由0.072 mm降至0,总脱碳层由0.142 mm降至0.063 mm,弹簧的疲劳寿命由17.7万次提高到23.2万次。