C、N元素对304不锈钢冷冲压成形性能的影响

304不锈钢具有良好的冷加工成形性,但其成分中各元素含量的不同将导致该材料冷加工成形性能差异很大。通过拉伸试验、杯突试验及拉深成形试验,研究分析了C、N元素对304不锈钢冷轧薄板拉深、胀形等冷冲压成形性能的影响。研究结果显示,C、N元素的增加有利于提高304不锈钢材料的延伸率、屈服强度、抗拉强度及硬度,并在适当的范围内可提高冷冲压胀形成形性能,但对冷冲压拉深成形性能不利;同时C元素对材料延伸率及冷冲压成形性能的影响比N元素显著。     

深冲用0Crl8Ni9Cu2奥氏体不锈钢冷轧板成形性试验研究

通过单轴拉伸试验求得的应变硬化指数n值和塑性应变比r值，是当今世界公认的用来评定金属薄板成形性优劣的重要参数。本文通过对太钢新开发的深冲用0Crl8Ni9Cu2奥氏体不锈钢冷轧板进行成形性试验研究，探讨了其成形性的优劣并提出了改进措施。     

铍板材深冲压成形异形件探讨

冲压成形是金属板材加工异形件的最基本方式。金属材质不同,冲压成形异形件的难易程度不同,主要影响因素是冲压成形性能和冲压成形极限。文章结合铍板材的冲压成形性能和冲压成形极限,对铍板材冲压成形异形件的难易性作了探讨。     

冷轧SUS301和SUS304不锈钢表面硬度控制工艺优化研究

基于具体生产机组设备和工艺条件,对SUS301和SUS304硬态不锈钢的冷轧生产工艺规程和工艺参数进行了研究,分析确定了硬态不锈钢生产过程中表面硬度的相关工艺参数,提出了针对硬态不锈钢生产的冷轧工艺规程调整方法,并利用BP神经网络建立了压下率设定模型,建立了宝新公司自有的硬态不锈钢表面硬度的工艺控制技术。相关技术应用于实际生产后,SUS301和SUS304硬态不锈钢产品的表面硬度控制精度明显提高。     

B443超低碳氮铁素体不锈钢的研究

为开发价格昂贵的SUS304奥氏体不锈钢的替代产品,试验研究了不同含量C N和Nb,Ti稳定化对B443系列铁素体不锈钢再结晶组织、力学性能、点蚀电位的影响.试验结果表明,Nb,Ti双稳定化提高了B443铁素体不锈钢的再结晶温度和点蚀电位.在试验室研究基础上,宝钢不锈钢分公司试制了B443NT超低碳氮铁素体不锈钢.该产品不仅具有与SUS304相当的耐腐蚀性能,而且具有优良的深拉伸性能和满意的焊接性能,可用于运输、建筑、厨具等众多行业.     

不锈钢成形极限曲线图（FLD）拉压区试验研究

通过采用不同试样形状、不同润滑方式对成形极限曲线图左半部分试验的影响进行研究，找出了试样形状及润滑方式对不锈钢薄板成形极限曲线图左半部分的影响规律，提出了进行不锈钢薄板成形极限曲线图左半部分试验用最佳试样系列及润滑方式。     

建筑用高耐蚀性铁素体不锈钢B445R的研制

宝钢研制出了建筑屋顶装饰用铁素体不锈钢B445R毛面产品。该产品的耐蚀性比奥氏体不锈钢SUS316L更优越,成本也比SUS316L低,采用常规的成形方法就可以将其加工成屋顶面板。此外,由于该产品的热膨胀系数比SUS316L小,故其热变形也比SUS316L小,同时由于进行了毛化处理,其表面具有较低的光反射能力。所有这些优点使其有能力成为沿海地区建筑物的屋顶装饰材料。     

铜含量对深冲用304J1奥氏体不锈钢力学性能的影响

试验用304J1奥氏体不锈钢(/%:≤0.08C、≤1.70Si、≤3.00Mn、15～18Cr、6～9Ni、1～3Cu)经10kg真空感应炉熔炼,锻成Φ40 mm钢棒,并经1080℃10 min,固溶处理、水冷。试验研究了0.05%～2.52%Cu对试验钢(/%:0.054～0.068C、0.45～0.63Si、1.82～1.95Mn、17.26～17.62Cr、6.42～6.49Ni)力学性能的影响,并对比分析了试验钢304J1和304DDQ深冲钢(/%:0.04C、0.32Si、1.17Mn、18.11Cr、8.66Ni)的30%冷变形产生50%马氏体的温度-冷加工诱变马氏体转变点M_d30,堆垛层错能和深冲杯凸(CUP)值:得出将304J1钢铜含量目标成分设定为1.50%时,室温力学性能、冷加工塑性、深冲性能及经济性的匹配性最佳。工业生产表明,1.50%Cu 304J1钢0.27 mm板的深冲值≥13 mm与304DDQ钢相当。     

304不锈钢薄板的延伸率与冷加工成形性关系研究

分析研究了304钢种不同C、N含量对延伸率及拉深、翻孔冷加工成形性能的影响,采用单向拉伸试验研究了不同拉伸速率、试样规格与304—2B不锈钢冷轧薄板延伸率测量值的关系。得出延伸率测量值随拉伸速率的提高而下降、随试样横截面的增大及C、N含量的增加而提高,翻孔及拉深成材率随C、N含量的增加而下降。说明在冷冲压用304不锈钢选材时,应综合考虑材料的化学成份、延伸率测量值以及拉伸试验参数,只有在拉伸试验条件及化学成份一致的情况下,延伸率测量值才能作为选材的依据之一。     

高塑性 Cr-Mn-Ni-Cu-N 奥氏体不锈钢 YGA201的研制

在实验室采用200 kg非真空感应炉研制了成分(％)为:≤0．10C,5．0-9．5Mn,16．0-19．0Cr, 3.5～5.5Ni,1．0～2.0Cu,≤0.2N的奥氏体不锈钢YGA201。力学性能和腐蚀试验结果表明,YGA201不锈钢含1．0％-2．0％Cu,使其1 050℃固溶处理后的延伸率达60％,高于ASTM201不锈钢(延伸率44％),该钢热加工性能和1 mol／L H₂SO₄中的耐腐蚀性能与SUS304(18Cr-8Ni)不锈钢相当。     

Prediction and Control of Wrinkle and Fracture for Stamping Regular Polygonal Box

Based on the deformation characteristic of regular polygonal box stamped parts and the superfluous triangle material wrinkle model, the criterion of regular polygonal box stamped parts without wrinkle was deduced and used to predict and control the wrinkle limit. According to the fracture model, the criterion of regular polygonal box stamped parts without fracture was deduced and used to predict and control the fracture limit. Combining the criterion for stamping without wrinkle with that without fracture, the stamping criterion of regular polygonal box stamped parts was obtained to predict and control the stamping limit. Taken the stainless steel 0Cr18Ni9 (SUS304) sheet and the square box stamped part as examples, the limit diagram was given to predict and control the wrinkle, fracture and stamping limits. It is suitable for the deep drawing without flange, the deep drawing and stretching combined forming with flange and the rigid punch stretching of plane blank. The limit deep-drawing coefficient and the minimum deep-drawing coefficient can be determined, and the appropriate BHF (blank holder force) and the deep-drawing force can be chosen. These provide a reference for the technology planning, the die and mold design and the equipment determination, and a new criterion evaluating sheet stamping formability, which predicts and controls the stamping process, can be applied to the deep drawing under constant or variable BHF conditions.     

Investigations of Forming Behaviour in Laser Shock Forming

The continuing trend of miniaturization has entailed the need for new cost efficient and fast methods for processing small parts. In this paper a new non‐mechanical process for the forming process of micro deep drawing is presented. This new deep drawing process utilizes a laser initiated plasma shock wave at the target, which forms the sheet. Several pulses can be applied at one point and therefore high forming degrees can be reached without increasing the energy density. In this paper the pressure of the shock wave is measured in order to enable optimizations of the process in future. Furthermore, an analysis of the thickness distribution over the deep drawn cups will be introduced. Laser deep drawing of samples made of Al99.5, Cu and stainless steel sheet metal with thicknesses of 20 μm and 50 μm are shown. Finally the efficiency of the laser shock forming process in calculated.     

Metallurgical Studies of Austenitic Stainless Steel 304 under Warm Deep Drawing

Austenitic stainless steel 304 was deep drawn with different blank diameters under warm conditions using 20 t hydraulic press. A number of deep drawing experiments both at room temperature and at 150 ℃ were conducted to study the metallography. Also, tensile test experiments were conducted on a universal testing machine up to 700 ℃ and the broken specimens were used to study the fractography of the material using scanning electron microscopy in various regions. The microstructure changes were observed at limiting draw ratio （LDR） when the cup is drawn at different temperatures. In austenitic stainless steel, martensite formation takes place that is not only affected by temperature, hut also influenced by the rate at which the material is deformed. In austenitic stainless steel 304, dynamic strain regime appears above 300 ℃ and it decreases the formability of material due to brittle fracture as studied in its fractography. From the metallographic studies, the maximum LDR of the material is observed at 150 ℃ before dynamic strain regime. It is also observed that at 150 ℃, grains are coarse in the drawn cups at LDR.     

节镍无磁不锈钢Cr18Ni6Mn3N的组织及性能

研究了节镍无磁不锈钢Cr18Ni6Mn3N的热轧及固溶后的力学性能和耐蚀性能,分析了其固溶和时效析出后的组织演变规律、冷变形过程中形变诱发马氏体相变及其磁性能.结果表明:该不锈钢的固溶组织为单相奥氏体,其力学性能和耐蚀性能均高于SUS304不锈钢;800℃保温4 h后,在晶界析出粒状氮化物,随着保温时间延长,逐渐沿晶界凸起片层状析出物并向晶内生长,保温20 h后,凸出的片层状析出物直径达20μm.冷轧压下率18.3%时尚未发现形变诱发马氏体组织,随着变形量增大,马氏体含量增多,磁导率上升,但与相同条件下的SUS304不锈钢相比,冷轧板固溶后相对磁导率可降至1.002,因此可用于低成本无磁不锈钢领域.      

残余元素Pb、Sn对含Cu奥氏体不锈钢表面质量的影响

研究了电弧炉+AOD和转炉+VOD冶炼的奥氏体不锈钢SUS304HC(%:≤0.06C、18～19Cr、8～11Ni、2～3Cu)和201Cu(%≤0.08C、7.5～10.0Mn、14～17Cr、4～6Ni、2～3Cu)中Sn、Pb等残余元素含量对初轧坯角裂和环向裂纹以及盘条表面横向裂纹的影响,并分析了残余元素的来源和控制措施。结果表明,当钢中Pb含量超过0.001%或Sn含量超过0.011%时,不锈钢热塑性降低,轧坯角裂倾向增加;控制炉料中残余元素含量是降低钢中Pb、Sn含量,提高初轧坯表面质量的有效措施。     

鞍钢高品质汽车板的研制开发

介绍了鞍钢目前已经开发出的以IF钢为代表的深冲钢系列品种,以烘烤硬化钢为代表的高强深冲钢系列品种,以DP、TRIP钢为代表的先进高强钢系列品种,以05板为代表的高表面质量的冷轧板系列品种,并根据用户的个性需求,开发出了具有不同特性的冷轧钢板。今后,鞍钢将通过新一代汽车用钢的开发和应用技术研究,为汽车行业的轻量化进程提供有力的技术支持。     

冷轧深冲用钢生产工艺改进

冷轧深冲用钢通过试制改进后采用无间隙原子钢材质,并对热轧工艺、冷轧工艺、退火工艺等进行调整。工艺调整后材料具有高的塑性应变比、高的应变硬化指数、低的屈服强度,使材料具有优良的成型性能,最终产品满足了用户的使用要求。     

SX55冷轧双相钢成型性能评定

在“七五”期间,鞍钢开发并生产出冷轧罩式炉退火双相钢(SX55),本文阐述SX55钢研制中的成型性能评定,指出该材料具有优越的拉胀成型性能、理想的拉深成型性能及较差的平面应变成型性能,据此,指导生产试冲及应用,取得了较好的效果。