烘烤硬化高强深冲冷轧汽车板BH340的研制开发

介绍了烘烤硬化高强深冲冷轧汽车钢板BH340的开发.试验证明,鞍钢生产的烘烤硬化冷轧钢板BH340是具有适中烘烤硬化值(BH值)及良好成形性的汽车用钢,能够满足汽车实际生产工业的要求.     

鞍钢A220BH烘烤硬化冷轧钢板的开发

介绍了鞍钢Ａ２２０ＢＨ烘烤硬化冷轧钢板的开发,研究了预应变,时效温度,保温时间对烘烤钢板硬化值的影响,测定了时效指数,试验证明,鞍钢生产的烘烤硬化钢板是屈服强度≥２２０ＭＰａ,具有适中烘烤硬化值及良好成形性汽车用钢板,能够灌汽车实际生产需要。     

成分对超低碳高强度烘烤硬化钢板性能的影响

研究了Ｐ、Ｔｉ，Ｃ，Ｎ等元素对超低碳高强度烘烤硬化（ＢＨ）钢板的强度、塑性和烘烤硬化值的影响，结果可见，Ｃ０．００４％，Ｎ０．００４７％，Ｐ０．０９４％，Ｔｉ０．０１７％的钢板具有较好的综合性能。     

汽车用钢板研究开发的现状及发展

本文评述了超深冲ＩＦ钢，低合金高强度钢，固溶强化高强度钢－含磷钢，双相钢，烘烤硬化钢，高强度可焊钢板和耐磨板等汽车用钢板研究开发的现状及发展。     

合金化热镀锌烘烤硬化钢板退火工艺研究

热镀锌烘烤硬化钢板在汽车外覆盖件上的应用越来越普遍。文章针对合金化热镀锌340BH烘烤硬化钢板,结合某公司热镀锌生产线的特点,在340BH烘烤硬化钢板成分分析的基础上,对连续退火工艺进行了改进:1)对340 BH钢板的均热温度、均热时间等工艺参数进行了研究分析,提出了最优化的退火工艺参数;2)对退火后的钢板性能进行分析,结果表明,达到用户的性能要求;3)生产工艺应用于实际生产,实现340BH烘烤硬化钢板的稳定生产。     

汽车钢板

烘烤硬化高强度钢板 汽车大型覆盖件,由于零件中间变形量小,加工硬化作用不明显,汽车在行驶中,零件经常受沙石或者重物的碰击,在零件表面产生凹陷,为避免这种情况,希望钢板有较高的“抗凹陷性能”,一般认为,屈眼强度越高,抗凹陷能力越强。但屈服强度越高,钢板的冲压     

镀锡板的烘烤硬化特性研究及其应用

镀锡板在完成退火平整后还会经过两次低温烘烤，即电镀工序的软熔处理和印铁环节的涂膜固化。通过镀锡板不同生产阶段力学性能及组织的分析测试，研究其烘烤硬化特性，为镀锡板的成分及工艺设计提供支撑。结果表明：MR系列镀锡板的烘烤硬化特性与冷轧退火方式密切相关，连退方式有烘烤硬化特性，罩退方式无烘烤硬化特性；连退方式镀锡板的烘烤硬化特性根据碳的质量分数及退火处理后的组织晶粒度的不同表现略有差异，但总硬化值都在40～60 MPa;用于承载要求高的三片罐身、瓶盖等产品时，可以利用间隙固溶原子的存在调节钢板的强度，降低冷轧轧制难度。     

预变形和烘烤条件对ELC—BH钢板性能的影响

实验表明，随着烘烤温度和预变形量的增加，ＥＬＣ－ＢＨ钢板的烘烤硬化性增加，但预变形量超过一定值时ＢＨ值反而下降；烘烤时间对ＢＨ值的影响与预变形量的影响趋势相同，但ＢＨ值变化范围很小。适当调整预变形量，烘烤温度和时间三个变量可使其ＢＨ值达到饱和，得到最佳硬化。     

平整和自然时效对超低碳烘烤硬化钢板性能的影响

研究了平整率(0～3.3%)和自然时效对830℃退火0.7 mm超低碳烘烤硬化钢板(%:0.003 0C、0.008Nb-0.003 Ti、0.003 0N和0.0030C、0.012Nb-0.012Ti、0.004 2N)力学性能和烘烤硬化性能的影响。结果表明,最初随平整率增加,由于柯氏气团减少和位错密度增加,屈服强度降低;当0.008Nb-0.003 Ti钢平整率达到0.48%,0.012Nb-0.012Ti钢平整率达到0.26%时,屈服强度降至最低;平整率继续增加由于冷加工硬化增强,钢的屈服强度升高。平整率过低和过高,均会导致烘烤硬化性能下降。平整率控制在0.5%～1.5%时,钢板能获得较低的屈服强度、较高的断后伸长率和最大的烘烤硬化性能。钢板经自然时效3个月,烘烤硬化性能和延伸率下降。     

连续退火工艺对超低碳烘烤硬化钢烘烤硬化性能的影响

应用连续退火模拟机研究了连续退火工艺各个参数对超低碳烘烤硬化钢板烘烤硬化性能的影响。试验结果表明:提高退火温度可增加NbC的回溶量,而且晶粒尺寸增大使碳原子的晶界偏聚量减少,从而提高了钢板的烘烤硬化性能;提高缓冷段冷速能减少NbC析出,有利于烘烤硬化性能的提高;快冷段冷速和过时效温度对烘烤硬化性能均无明显影响;提高过时效后冷速使碳原子向晶界偏聚的时间缩短,对于提高烘烤硬化性能也是有利的。     

Bake Hardening of Hot Rolled Multiphase Steels under Biaxial Pre‐strained Conditions

Multiphase steels show a strong bake hardening effect being of importance for shaping of car body structural parts. The raised yield strength is exploited for improved crash resistance. Especially the automotive industry has a growing interest in using this effect. Normally the bake hardening effect is examined in tensile tests whereas under industrial conditions shaping of structural parts shows a wide spread of stress strain behaviour, from uniaxial conditions over plain strain to biaxial ones. So it is obvious that the bake hardening behaviour of a material cannot be described with results of the uniaxial tension test only. To give a first answer to this question, the dependence of the bake hardening effect on different biaxial prestrains was investigated for several hot rolled multiphase steels using various baking temperatures and holding times whereas the bake hardening effect under uniaxial prestrain had already been examined in [5]. Considering the choices to generate biaxial strain, a Marciniak forming tool with a diameter of 250 mm mounted on a 2500 kN hydraulic press was chosen. For control of plastic deformation and adjustment the non‐contact measuring system ARGUS, was used. To reduce the quantity of experiments “Design of Experiments” and statistical methods were applied for a martensitic steel, a dual phase steel, a complex phase steel, a ferrite‐bainite steel, and a retained austenite steel known as TRIP, all in hot rolled condition. As a result, a formula for yield stress, tensile strength and residual deformability was developed. Furthermore, a method was found to predict easily whether a steel under investigation is qualified for additional experiments in regard to bake hardening or more exactly its response to different baking temperatures and holding times.     

Microstructure and Properties of Ti and Ti+Nb Ultra-Low-Carbon Bake Hardened Steels

Hot rolling, cold rolling and continuous annealing processes of Ti bearing and Ti+ Nb stabilized ultra-low-carbon bake hardened steels were experimentally studied. The microstrueture and texture evolution, as well as the morphology, size and distribution of second phase precipitates during hot roiling, cold rolling and continuous annea-ling were also analyzed. The results showed that the size of NbC precipitates in Ti+ Nb stabilized ultra-low-carbon bake hardened steel was smaller than that of TiC precipitates in Ti bearing ultra-low-carbon bake hardened steel, which made the average grain size of Ti+ Nb stabilized ultra-low-carbon bake hardened steel finer than that of Ti bearing ultra-low-carbon bake hardened steel; for the yield strength, the former was higher than the latter; but for the γ value which reflects the deep-drawing performance, the former was lower than the latter.     

影响电镀锌镍烘烤硬化钢屈服强度的因素分析

介绍了电镀锌镍烘烤硬化钢的特性和其冲压过程中材料本身性能的变化,并研究了生产工艺对其重要力学性能指标--屈服强度的影响,对于理论研究和生产实践具有一定的指导意义.     

各向同性钢与烘烤硬化钢的烘烤硬化性和抗凹陷性

 研究了烘烤温度、烘烤时间和预拉伸应变量对罩式炉退火工艺生产的各向同性钢的烘烤硬化性的影响，并与力学性能相当的冷轧烘烤硬化钢进行了对比。结果表明，在不同的烘烤条件下，各向同性钢的烘烤硬化值均低于同样强度级别的烘烤硬化钢。抗凹陷性测试结果表明，各向同性钢的抗凹陷性低于烘烤硬化钢。汽车外板实物分析结果表明，两种钢冲压成形后再烘烤，其屈服强度几乎没有提高。     

Strain Limit of Extra Galvannealed InterstitialFree and Bake Hardened Steel Sheets Under Different Stress Conditions

The formability of bake hardened steel （thickness 0.82 mm）, and the extra galvannealed IF steel （thickness 0.82 mm） have been studied. The suitability of the above steels for forming applications has been critically examined. The microstructure, tensile properties, and formability parameters of the above sheet metals were determined. The manufacturing process of the steels and the significance with reference to its formability were studied.     

Bake Hardening of Laser Welded Dual Phase Steel

The influence of bake hardening on the mechanical properties of laser welded dual phase steel was investigated. A remarkalbe increase of the hardness in the zone influenced by laser welding was observed. The fusion zone had a low carbon lath martensite microstructure. The laser weld region had a higher interstitial carbon content than the base material. The dual phase steel exhibited a clear bake hardening effect in both the as‐received and the laser‐welded conditions. The bake hardening effect is more pronounced in the prestrained laser welded condition. A pronounced decrease of the ductility was observed for prestrained laser welded DP steel.     

Influence of Carbon on Mechanical Properties of Cu bearing Extra Low Carbon Steel Sheets

This paper examines the effect of carbon (C) on solid solution strengthening, bake hardening and anti‐strain aging property for copper (Cu) bearing extra low carbon (ELC) steel sheets. For this purpose, five ELC steels that contain different content of C were selected. We have investigated the effect of C on mechanical properties and microstructures for the continuous annealed ELC steel sheets. Mechanical properties and microstructures were analyzed as well using uni‐axial tensile test and electron back‐scattered diffraction (EBSD) technique following pilot rolling and continuous annealing. It has been found that the addition of C increases the solid solution strengthening as well as 19.9MPa per 0.0010wt%C in yield strength. What is more, the addition of C increases the bake hardenability (BH) as well as 18.7MPa per 0.0010wt%C. In addition, the addition of C delays the recrystallization during continuous annealing process. From an industrial standpoint, it is possible to control both a stable anti‐strain aging property and high bake hardenability for the ELC steel sheets without Ti and Nb addition.     

不同成分体系对超低碳烘烤硬化钢性能的影响

研究了不同成分体系超低碳烘烤硬化钢的性能特征,生产结果表明:Ti-BH钢屈服强度和BH值较低,伸长率和"值富裕量较大,并且BH值波动较大.通过对不同成分体系钢板的微合金化原理进行分析,确定了不同成分体系烘烤硬化钢性能不同的原因,并据此将烘烤硬化钢的成分体系由Ti-ULC改为Nb+Ti复合体系.更改后的烘烤硬化钢性能指标...