汽车用先进高强度钢的开发及应用进展

 先进的高强度钢在汽车减重、节能、提高安全性、降低排放等方面展现出了广阔的前景,在新一代汽车伙伴计划、超轻钢车身——先进概念车等项目上得到了应用和推广。简述了先进高强度汽车用钢板的最新开发和应用进展情况。     

Strain Hardening and Strain Rate Sensitivity Behaviors of Advanced High Strength Steels

 The mechanical properties of commercial dual phase (DP), transformation induced plasticity (TRIP), and high strength low alloy (HSLA-340) steel sheets are investigated and compared at various strain rates ranging from 0. 0017 to 0. 17 s-1 at ambient temperature. TRIP steel outperforms the other two materials, having comparable ductility and twice as large strength relative to DP steel. TRIP has larger strength and much larger ductility than HSLA-340. The exceuent ductility of TRIP800 is due to its high strain hardening capability, which promotes stable plastic deformation. It is observed that the strain hardening rate in TRIP800 does not decrease to zero at failure, as common in most materials in which failure is preceded by necking.     

Effect of Heat Treatment on Delayed Fracture Resistance of High Strength Steel 30CrMnSi2NiNb

Ｔｈｅｄｅｌａｙｅｄｆｒａｃｔｕｒｅｉｓｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒ ｔａｎｔｆａｉｌｕｒｅｍｏｄｅｓｆｏｒｈｉｇｈｓｔｒｅｎｇｔｈｓｔｅｅｌｓａｐｐｌｉｅｄｔｏｈｅａｖｙｄｕｔｙｍａｃｈｉｎｅｃｏｍｐｏｎｅｎｔｓｓｕｃｈａｓｈｉｇｈｓｔｒｅｎｇｔｈｂｏｌｔｓ[1] .Ｉｎｐｒｅｖｉｏｕｓｉｎｖｅｓｔｉｇａｔｉｏｎｓ ,ｉｔｗａｓｓｈｏｗｎｔｈａｔｔｈｅｄｅｌａｙｅｄｆｒａｃｔｕｒｅｒｅｓｉｓｔａｎｃｅｏｆｈｉｇｈｓｔｒｅｎｇｔｈｓｔｅｅｌｉｓｉｎｔｅｎｓｉｖｅｌｙｄｅｐｅｎｄｅｎｔｏｎｉｔｓｃｈ…     

Delayed Fracture Behavior of CrMo-Type High Strength Steel Containing Titanium

Generally ,thequenchedandtemperedlowalloysteelswithtensilestrengthabove 12 0 0MPaaresus ceptibletohydrogen induceddelayedfracture(HIDF) [1,2 ] .Extensivestudiesonthedelayedfracturebehaviorofhighstrengthsteelshavebeenperformedtheseyears,butthesatisfactorys…     

Delayed Fracture Behavior of CrMo Type High Strength Steel Containing Vanadium

The quenchedandtemperedlowalloysteelswithtensilestrengthexceeding 12 0 0MPaaresus ceptibletohydrogen induceddelayedfracture(HIDF )wheninuse[1,2 ] .Despitetheenormousamountofresearchworkperformedondelayedfrac tureofhighstrengthsteelintheseyears ,thesolu tiontothisproblemstillhasnotbeenobtained .TheresistanceofanalloytoHIDFisstronglyaffectedbytheinteractionofhydrogenwithmicrostructuralhet erogeneitiesthatactashydrogentraps ,andthere foreinasearlyas 1980s ,GMPressouyre[3 ] suggest edtheappli…     

The Tensile Response and Fracture Behavior of Four High Strength Specialty Steels

In this technical paper the role of alloy chemistry and secondary processing on tensile response and final fracture behavior of four high strength steels is presented and discussed. The conjoint influence of composition, secondary processing and intrinsic microstructural features in governing stress versus strain response and tensile properties is highlighted. The macroscopic mode and intrinsic microscopic features that result from final fracture of the four high strength steels is discussed. The intrinsic microscopic mechanisms governing tensile deformation and final fracture behavior of the high strength steels are outlined in light of the specific role played by composition, intrinsic microstructural effects and nature of loading.     

Precipitation Behavior of FeTiP in Ti-added Interstitial Free High Strength Steels

The precipitation behavior of FeTiP in interstitial free high strength(IFHS)steels has been studied by using a transmission electron microscope(TEM).The results show that the TiC particles,appearing at earlier stage,are more stable than the FeTiP ones during recrystallization annealing at the two given temperatures(810℃ and 840℃).Therefore,the FeTiP particles can only be observed in the steels with sufficient amount of Ti.There is a critical forming time for the FeTiP,which is between 90-120 sat 810 ℃ and 60-90 sat 840 ℃.The precipitation of FeTiP involves two steps,i.e.the formation of FeTi precursors and the diffusion of P.The former step determines the reliance of Ti content for the precipitation of FeTiP,whereas the latter step leads to the difference in the critical annealing time.     

鞍钢先进高强汽车用钢的研制开发

介绍了鞍钢先进高强汽车用钢开发研制情况,包括以980 MPa级DP钢、TRIP钢、TWIP钢和QP钢为代表的热轧、冷轧和热镀锌先进高强钢系列产品,以及鞍钢开发的先进高强钢热镀锌生产技术,并对鞍钢先进高强汽车钢未来的发展方向进行了展望。     

先进的高强度钢及其在汽车工业中的应用

对先进的高强度钢及其在汽车工业中的应用进行了评述，详细介绍了先进的高强度钢的定义、范围、性能特点，高的应变硬化特性，成形性、回弹等，以及成形构件的性能，硬化增量及撞击吸能；最后介绍了这类钢的发展趋势和在汽车轻量化中的应用前景。     

Effect of Boron on Delayed Fracture Resistance of Medium-Carbon High Strength Spring Steel

The delayed fracture behavior of medium-carbon high strength spring steel containing different amounts of boron (0.000 5%, 0.001 6%) was studied using sustained load delayed fracture test. The results show that delayed fracture resistance of boron containing steels is higher than that of conventional steel 60Si2MnA at the same strength level and it increases with the increase of boron content from 0.000 5% to 0.001 6%. The delayed fracture mode is mainly intergranular in the boron containing steels tempered at 350 ℃, which indicates that the addition of boron does not change the fracture character. However, the increase of boron content enlarges the size of the crack initiation area. Further study of phase analysis indicates that most boron is in solid solution, and only a very small quantity of boron is in the M3(C, B) phase.     

钛对高强度钢耐延迟断裂性能的影响

在42CrMo钢中加入不同含量的微合金元素钛，研究了钛对高强度钢耐延迟断裂性能的影响。试验结果表明，钢中添加适量的钛能够改变高强度钢的耐延迟断裂性能，这种影响主要来自于析出物TiC的氢陷阱作用和晶粒细化作用。     

1300 MPa High Strength Steel for Bolt with Superior Delayed Fracture Resistance

Ｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｍｏｄｅｒｎｉｎｄｕｓｔｒｙ ,ｔｈｅｒｅｉｓａｉｎｃｒｅａｓｉｎｇｄｅｍａｎｄｆｏｒｈｉｇｈｓｔｒｅｎｇｔｈｓｔｅｅｌｓｗｉｔｈａｔｅｎｓｉｌｅｓｔｒｅｎｇｔｈｅｘｃｅｅｄｉｎｇ 12 0 0ＭＰａｔｏｂｅｕｓｅｄｆｏｒｈｉｇｈｅｒｓｔｒｅｎｇｔｈｂｏｌｔｓｉｎｔｈｅｃｏｎｓｔｒｕｃｔｉｏｎｉｎ ｄｕｓｔｒｙ ,ａｕｔｏｍｏｂｉｌｅ ｐａｒｔｓ ,ｌｏｎｇ ｓｐａｎｓｕｓｐｅｎｓｉｏｎｂｒｉｄｇｅｓ,ａｎｄｓｏｏｎ[1] .Ｈｏｗｅｖｅｒ ,ｆｏｒｑｕｅｎｃｈｅｄａｎｄｔｅｍｐ…     

高强度钢42CrMoVNb的氢致延迟断裂行为

采用阴极充氢、SSRT缺口拉伸和氢热分析等试验方法,研究了高强度钢42CrMoVNb在不同温度回火状态下的延迟断裂行为,并与常用的机械制造用钢42CrMo进行了对比。结果表明,随着回火温度的升高,试验钢的耐延迟断裂抗力逐渐提高;在相同回火温度下,由于42CrMoVNb钢的强度水平明显高于42CrMo钢,其耐延迟断裂抗力...     

裂解连杆用高强度非调质钢的研制

设计了用于裂解连杆的高强度非调质钢及其生产工艺,通过金相显微镜、扫描电镜等方法,分析了钢的显微组织、析出相及其对力学性能的影响。结果表明:组织由铁素体和珠光体组成,向钢中添加高的V和N元素,有利于增加更多的弥散析出相,提高其强度。轧后加速冷却,有利于铁素体晶粒细化、珠光体球团尺寸和珠光体片层间距减少、析出相增多,使其抗拉强度和屈服强度分别达到1 000 MPa和750 MPa以上。     

我国铁道车辆用高强度耐大气腐蚀钢的进展

回顾了我国铁道车辆用耐大气腐蚀钢的现状，提出了在高速重载条件下铁道车辆及其用钢的新要求。初步总结了我国高强度耐大气腐蚀钢的研究工作，对比分析了国内几个主要钢厂开发生产的高强度耐大气腐蚀钢的工艺性能。     

一种2000 MPa级中碳高强度弹簧钢的疲劳破坏行为

 研究了一种2 000 MPa级中碳高强度弹簧钢的疲劳破坏行为。升降法得出实验钢的旋转弯曲疲劳极限σ-1为810 MPa，此值明显高于传统弹簧钢；这主要得益于实验钢具有良好的强度和塑韧性配合及均匀细小的奥氏体晶粒。用SEM对疲劳断口的分析表明，实验钢的疲劳破坏均起源于试样表层的非金属夹杂物，其主要成分为含Ti和V的碳氮化物，平均尺寸为(50±10)μm，且呈“鱼眼”断裂。相对于试样心部的夹杂物，表层夹杂物对实验钢的疲劳性能的危害性更大。     

Effects of Processing Variables on Microstructure and Yield Ratio of High Strength Constructional Steels

The process of “controlled rolling+relaxation+ultra fast cooling (UFC)”for high strength constructional steel with low yield ratio was presented.Microstructure and corresponding relationship with low yield ratio were in-vestigated.The results showed that the constructional steels with multiphase microstructure of bainitic ferrite,mar-tensite-austenite (M-A)and lath bainite were obtained through the creative process.The grain size decreased with the decrease in finish rolling temperature,which enhanced the strength by the grain refinement strengthening.The proper relaxation treatment promoted the bainitic ferrite lath width and the formation of blocky M-A constituent.In addition,both the tensile and yield strength increased with the decrease in finish rolling temperature and UFC final temperature,but the yield strength increased more significantly than tensile strength,which caused the increase in yield ratio.By using the process of “controlled rolling+relaxation+ultra fast cooling”,the excellent comprehensive mechanical properties of 780 MPa grade constructional steels of 12-40 mm in thickness were achieved.     

HQ130＋QJ63高强钢焊接接头的组织与性能

采用光镜，电镜，冲击和拉伸等试验方法，对气体保护焊“低强匹配”焊材焊制的ＨＱ１３０＋ＱＪ６３高强钢焊接接头的显微组织和力学性能进行了试验研究，并采用模拟焊接热循环的方法研究了不同峰值温度和冷却时间对ＨＱ１３０钢热影响区（ＨＡＺ）组织和冲击韧性的影响，试验结果表明，受焊接热循环影响，ＨＱ１３０钢ＨＡＺ存在回火软化区，该区域软化或失强最大的部位在峰值加热温度为Ａｃ１附近。在ＨＡＺ峰值温度Ａｃ１～Ａｃ３