热等静压用半球形钢包套的拉深模具设计

热等静压HIP是铍材成型生产的重要组成部分。简述了热等静压用半球形钢包套的工艺要求,提出了使用冲压拉深模具加工半球形包套的加工方法,讲述了包套拉深模具的设计,着重讲述了模具设计的要点,以及包套的使用效果。     

不锈钢筒形件深拉深新工艺

传统工艺中,1Cr18Ni9Ti不锈钢板料需多次拉深加工,其生产周期长、产品成本高、生产效率低.通过实验探究,在合理地调整凹、凸模间隙,特别是采用新的润滑剂和润滑方法,同时取消或改变热处理方法的情况下,同样可以深拉深出表面质量理想的不锈钢筒形件.在整个生产工艺中,零件拉深成功的重要因素是合理选择和使用润滑剂,3种润滑剂的配合使用,保证了拉深过程的顺利完成.将该方法用于批量生产,模具寿命大大延长,并取得了很好的生产效益.     

深冲钢浸入式水口结瘤物分布及成分组成

对浸入式水口从不同位置分别进行取样,借助扫描电镜和能谱仪,观察不同位置的结瘤物宏观形貌和微观结构,并分析各个位置结瘤物的微观结构和成分组成.研究表明,浸入式水口结瘤物主要分为黄褐色结瘤物、白色结瘤物和冷钢3种;其中,黄褐色结瘤物的主要成分为Al2O3、Fe以及少量FeO和SiO2组成的混合物,白色结瘤物主要成分为Al2...     

Optimization of annealing parameters for improvement in formability of extra deep drawing quality steel

A number of annealing cycles were investigated in an attempt to find the optimum cycle that results in an attractive combination of mechanical and formability properties of an extra deep drawing (EDD) quality steel. It was found that the cycle that involved an intermediate anneal at 600 °C followed by further soaking at 700 °C resulted in the best combination of mechanical and formability properties. It was also found that the rate of heating up to 600 °C can be kept at 50 °C/h while the heating has to be done at a rate of 30 °C/h from 600 °C to the final annealing temperature of 700 °C. The desirable combination of mechanical and formability properties has been correlated with the microstructure that shows pancaking of the annealed grains accompanied by precipitation of carbides. Precipitates of carbides are more in number and smaller in size in the case of samples annealed by the cycle mentioned above compared to the ones annealed by other cycles. They are spherical in shape, which is desirable for forming applications.     

低成本深冲用200系列不锈钢的研制

采用正交表L9(34)安排试验,调整铜、锰、镍合金元素的含量,用100 kg中频感应炉开发出低成本深冲用200系列不锈钢,对其进行极差分析、力学性能和盐雾腐蚀性能试验.结果表明,低成本深冲用200系列不锈钢中的锰、铜、镍含量最佳配比为Mn10Ni1.0Cu0.5.不锈钢经过1050 ℃固溶处理后,其伸长率和杯突值分别为60%和13.8 mm,与SUS304相当;抗拉强度和屈服强度均高于SUS304;耐腐蚀等级达到10级,与SUS304相当,优于其他试验不锈钢.     

微碳低合金深冲双相钢的再结晶规律

研究了一种微碳低合金钢在罩式退火过程中的再结晶组织演变和再结晶动力学规律,根据Johnson-Mell理论和Arrhenius再结晶激活能的计算,建立了再结晶体积分数与退火温度和等温时间的热力学模型及退火温度与完全再结晶所需时间的动力模型。结果表明,两个模型相互得到验证,并都揭示了随退火温度的增加,再结晶孕育期和完成时间缩短的规律;在同一温度下,随保温时间的延长,再结晶体积分数增加直至完全再结晶。另外,发现在Ac₁附近退火时,存在再结晶与相变的竞争现象,当保温时间较短时以再结晶过程为主,而长时间保温时则以相变过程为主。     

深冲钢板的织构及塑性应变比r值的模型计算

检测了无间隙原子钢(IF钢)板的织构及板材与轧向夹角为0°、15°、30°、45°、60°、75°、90°的r值。模拟计算了Sachs模型和反应应力模型在体心立方结构12个{011}<111>滑移系开动情况下的拉伸变形规律。基于两个变形模型和板材的织构信息,计算了板材与轧向不同夹角时的r值。对不同模型的计算值与实测值进行了比较,分析了误差产生的原因。     

Comparison of formability of steel strips, which are used for deep drawing of stampings

The paper concerns evaluation and comparison of formability of steel strips, which are used in Czech Republic for production of intricate deep stampings. The properties of sheet-metal which have the principal influence upon the success of deep drawing or strech-forming are described. Two methods used for determination of strain-hardening exponent are compared. It is concluded, that the method according to SN 42 0436 is suitable for approximation of stress-strain curve of given sheet-metal only from point of view of functional values. The values of strain-hardening exponent, calculated by the method using maximum uniform elongation, are more strongly correlated with pure stretchability than are the values of it, calculated by the method according to SN 42 0436.     

Square cup deep drawing and 2D-draw bending analysis of Hadfield steel

Hadfield steel is the dominant material in the production of bullet proof steel helmet for military uses. The conventional bullet proof steel helmets are extensively fabricated by cold forming (deep drawing) 1.2 mm Hadfield steel sheets at room temperature. This paper presents the experimental analysis of the square cup deep drawing and 2D-draw bending of Hadfield steel as a continuation of an international bench mark research program organized by NUMISHEET'93 organising committee in Japan. The draw-in values of the flange have been determined for various punch travels in the square cup operation. The principal strains were evaluated in three directions from grid measurments for those punch travels. Springback values and sidewall curls were also described in 2D-draw bending operation. The experimental results were compared with that of ones in mild steel.     

不锈钢/铝(合金)/不锈钢多层复合板的冲压成型性能

通过实验测量了不锈钢／铝合金／不锈钢三层复合板和不锈钢／铝／铝合金／铝／不锈钢五层复合板的各项成型性能指标，并采用刚一塑性有限元方法对这2种复合板在有压边力条件下的冲压成型过程进行了计算模拟分析，获得了各组元金属的变形规律以及等效应力、应变分布图。分析结果证明：五层复合板的冲压成型性能要优于三层复合板。     

微碳深冲钢板的再结晶与{111}织构的形成过程

采用试验和微观组织分析的方法,研究了冷轧微碳深冲钢板的再结晶组织和织构的特点以及AlN相析出对{111}织构形成过程的影响.研究结果表明,{111}织构从再结晶的形核阶段就已经开始形成,而且在其形成和初始长大过程中吞噬了非{111}织构组分.退火时采用慢速升温有利于AlN相充分析出和长大,促进了{111}织构的形成,从而抑制了非{111}织构组分,提高了微碳深冲钢板的成形性能.     

滑块速度对DC06极限拉深系数的影响

基于测定DC06钢极限拉深系数,在KOMATSU H1F-60伺服压力机上进行滑块速度对极限拉深系数影响的实验,研发了"冲压成形性能测试系统",该系统可实现工艺曲线预存与调用、滑块运行曲线可以在正弦的基础上任意修正,具有能够实现最佳工艺条件、控制精度高及滑块位置精度在0.01mm、压边板、上模装有力传感器等特点,能够保证实验操作可行性及所得数据的精确可靠性。进行了多组实验及验证,以降低实验结果偶然性;实验结果与数值模拟结果对比表明,当滑块速度小于70%时,拉深实验的成品率逐渐下降,极限拉深系数与滑块速度呈现正比关系,即当滑块速度增加时,板料越容易拉破;当滑块速度达到90%时,其拉深实验的成品率反而上升,板料不易拉破。     

Improvement of formability in deep drawing of ultra-high strength steel sheets by coating of die

The formability of deep drawn ultra-high strength steel sheets in dies coated with either titanium nitride (TiN) or Vanadium carbide (VC) at different drawing speeds and ironing ratios was investigated. TiN was deposited via chemical vapour deposition and physical vapour deposition (PVD) while thermal diffusion was used for VC deposition. In non-coated dies, seizure occurred on both surfaces of the die and the side wall of the drawn cup irrespective of the deep drawing conditions. The deep drawability is improved with coating of die. Whereas in coated dies, seizure became significant only during deep drawing extreme conditions of 120 mm/s for TiN-coated dies; and this was prevented in VC-coated dies across all drawing conditions. The VC-coated die was suitable for deep drawing of ultra-high strength steel sheets. The delayed fractured observed in the ultra-high strength steel cups occurred for a large amount of ironing ratio and drawing speeds; and this can be prevented by appropriate heat treatment.     

压边间隙对圆柱杯反向深拉延成形质量的影响

对ＮＵＭＩＳＨＥＥＴ９９圆柱杯深拉延－－反向深拉延标准考题（Ｂｅｎｃｈｍａｒｋ－Ｃ）,进行了有限元数值仿真,将计算结果与Ｋｉｍ Ｈｙｕｎｇ ｊｏｎｇ的实验结果做了比较。在此基础上,分析了第一次拉延过程的工艺参数－－压边间隙对后续工序成形质量的影响,指出第一次成形的压边间隙在１．６￣１．８ｍｍ之间时,第二次成形的变形余裕度最大,即成形质量最好。研究说明,开展多工序成形过程的数值仿真有着重要的意义。     

Prediction of forming limit in hydro-mechanical deep drawing of steel sheets using ductile fracture criterion

It has been observed that the forming limit curve at fracture (FLCF) of steel sheets, with a relatively higher ductility limit have linear shapes, similar to those of a bulk forming process. In contrast, the FLCF of sheets with a relatively lower ductility limit have rather complex shapes approaching the forming limit curve at neck (FLCN) towards the equi-biaxial strain paths. In this study, the FLCFs of steel sheets were measured and compared with the fracture strains predicted from specific ductile fracture criteria, including a criterion suggested by the authors, which can accurately describe FLCFs with both linear and complex shapes. To predict the forming limit for hydro-mechanical deep drawing of steel sheets, the ductile fracture criteria were integrated into a finite element simulation. The simulation, results based on the criterion suggested by authors accurately predicted the experimetal, fracture limits of steel sheets for the hydro-mechanical deep drawing process.     

CSP卷取温度对冷轧深冲钢板的影响

研究了热轧卷取温度对CSP(compact strip production)冷轧深冲板的性能、组织和织构的影响。CSP热轧板组织主要为多边形铁素体,随卷取温度降低,晶粒尺寸略有减小。660℃和680℃卷取的成品冷轧板组织为等轴晶粒,卷取温度不超过600℃时则以"饼型"晶粒为主。力学性能测试表明,低于600℃卷取的成品板屈服强度和抗拉强度较低,其加权平均塑性应变比(rm)可达到1.80以上,伸长率超过49%。随卷取温度升高,成品板的{001}〈110〉和{110}〈110〉织构的取向分布密度逐渐升高,{111}织构取向分布密度先升高后降低,{111}〈110〉和{111}〈112〉织构取向分布密度差值也是先升后降。     

新型液压-机械拉深工艺试验研究

利用改进后的新型液压-机械拉深模具进行拉深试验研究.设计适合于改进后的新型液压-机械拉深模具的拉深工艺过程,对不同直径的板料进行拉深试验,每次试验没置不同的工艺参数,获得了拉深比达2.63的制件.试验表明,引入液压作用后,可以大幅度地提高板料的极限拉深比,随着板料直径的增加,使拉深成功进行的液压力区间逐渐减小.     

Electroconductive ceramic tooling for dry deep drawing

Large use and waste of lubricating oil has become a very serious environmental issue. Hence, oil-free metal forming is one of the most promising solutions to this issue. Among them, ceramic tooling is proposed because of its good tribological properties. Its feasibility for dry deep drawing has been studied in laboratory; ceramic tooling is thought to be applicable to dry deep drawing. However, the workability of ceramics in tooling preparation is inferior to that of alloy tool steel. In the present paper, electroconductive ceramics are proposed as an alternative tool material. The electroconductive ceramic tooling is shaped by electric discharge machining such as wire electric discharge machining, die sinking electric discharge, and so forth; any shape of tools can be easily accommodated by these methods. The workability of electroconductive ceramics by electric discharge machining as well as the deep drawability with electroconductive ceramics tooling is experimentally evaluated. Selection of electric conditions for electric discharge machining influences the surface finish quality of electroconductive ceramics. Zirconia-based electroconductive ceramic die has an equivalent deep drawability in dry to conventional SKD11 die with lubricant.