装甲钢焊缝区抗弹防护性能初步探讨

目的 初步探索装甲钢焊缝区的抗弹防护性能并提出防护能力提升措施。方法 通过对装甲钢焊接结构进行组织性能分析及抗弹性能测试,获得焊接对装甲车辆抗弹防护性能的影响规律,并对装甲车辆抗弹防护能力提升对策进行讨论。结果 装甲钢接头焊缝区宽度达到46 mm,焊缝中心硬度低于312HV,较母材区硬度降低40%以上;抗弹性能测试结果表明,焊缝区的抗弹性能较母材区的显著衰减,为提升装甲车辆整体抗弹防护能力,针对焊缝区薄弱点从焊接工艺控制、结构优化、加装防护组件3个方面进行讨论,并提出了相应的防护对策。结论 装甲钢焊缝区是抗弹防护的薄弱点,需通过一系列的防护措施减少焊缝区正面中弹概率,提高装甲车辆服役期间的抗弹防护能力。     

焊丝成分对超高强装甲钢焊接接头组织与性能的影响

利用气体保护电弧焊工艺完成了4.5 mm和9.0 mm超高强装甲钢的焊接,研究了焊丝(MG70S-6和ER307Si焊丝)成分对接头组织与性能的影响,通过光学显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)等表征方法对焊接接头各区域进行微观组织和物相结构的分析,并测试了接头的硬度分布、拉伸性能和冲击韧性。结果表明,焊接接头成形质量良好,无明显未熔合、气孔、裂纹等缺陷,焊缝区组织为片状马氏体、针状铁素体和少量粒状贝氏体,完全淬火区组织为马氏体和贝氏体,不完全淬火区组织为马氏体和铁素体,回火区析出网状渗碳体。焊接接头的热影响区软化现象较为明显,接头难以达到与母材等强,断裂主要发生在焊缝区,呈现出脆性断裂特征。采用ER307Si焊丝焊接的9.0 mm装甲钢接头的焊缝室温冲击功达到94 J,完全满足使用要求。     

低碳微合金直接淬火钢的组织与力学性能

为了提高低碳直接淬火钢的强韧性能,对一种低碳Nb-V微合金钢进行了轧后直接淬火(DQ)和再加热淬火(RQ)热处理实验,分析了低碳直接淬火钢的的强韧化机理.采用光学显微镜、透射电子显微镜、硬度计、拉伸试验机以及冲击试验机研究了轧后热处理工艺对低碳Nb-V微合金钢组织和力学性能的影响.结果表明,DQ工艺钢马氏体板条间距细小,含有较多的位错亚结构,因此具有较高的强度和韧性.DQ工艺钢马氏体中的大量位错,促进了碳化物弥散析出,产生了显著的二次硬化效果.由于基体中固溶的Nb、V等元素推迟淬火马氏体在回火过程中的各种转变,以及回火时析出的细小弥散碳化物抑制马氏体铁素体回复、再结晶过程,DQ工艺钢表现出较高的回火稳定性.     

淬火温度对5CrW2Si钢组织与性能的影响

研究了５ＣｒＷ２Ｓｉ钢经正火加调质预处理后，在不同淬火温度下的显微组织，测定了其σｂ，Ｋ１ｃ和等力学性能。给出了显微组织与性能的关系，确定了５ＣｒＷ２Ｓｉ钢最佳强韬性的热处理工艺。     

直接淬火低碳贝氏体钢的回火组织与力学性能

利用SEM,TEM等实验方法,研究了不同回火温度对直接淬火Fe-Mn-Mo-Nb-Ti系低碳贝氏体组织和力学性能的影响.结果表明,580℃回火后钢板具有最佳综合力学性能,抗拉强度805MPa,屈服强度719MPa,延伸率25.8%,-20℃冲击功106J.随回火温度的升高,板条贝氏体回复作用逐渐加强,位错通过运动、合并...     

低合金高强度钢的微观组织和疲劳裂纹扩展行为

用透射电镜观察了３０ＣｒＭｎＳｉＮｉ２Ａ钢等温的微观组织，疲劳裂纹扩展行为、裂纹尖端塑性区和位错结构，结果表明，等温状态组织由马氏体和贝氏体组成。在一个奥氏体晶粒内一般存在四个板条领域、裂纹尖端的塑性区内存在主位错带，疲劳断裂的基本组织单元为板条晶或板条束。裂纹遇到板条束界时方向发生较大偏斜。     

装甲钢/芳纶复合材料抗爆震性能研究

采用圆形炸药设计了平面波发生器,研究了不同结构的装甲钢/芳纶复合材料对冲击波的衰减效果.试验结果表明,在装甲钢上加装纤维复合材料板可提高其抗爆震性能,当材料按照波阻抗减小的顺序进行排列时,可更有效衰减冲击波,具有多层结构的材料比双层结构材料的衰减效果更优.     

35CrMoA钢激光淬火-渗氮复合改性层微观组织及脆性

研究了气体渗氮层和激光淬火-渗氮层的相组成、微观结构、显微硬度及脆性。结果表明, 激光淬火-渗氮白亮层中ε-Fe₃N含量由14.74%增至69.45%, 而脆硬的ξ-Fe₂N含量由79.95%降至25.03%。表层的N含量降低, 渗氮层N浓度曲线降低趋势平缓, N的总扩散通量增加, 渗氮层厚度增加。激光淬火-渗氮层组织晶粒细小致密, 渗碳体分布在条状下贝氏体组织中, 硬度高的Cr₂N颗粒数目增加, 白亮层显微硬度值显著提高, 渗氮层脆断的临界压力由气体渗氮层的3 N提高到激光淬火-渗氮层的6 N。      

热轧钛微合金化TRIP钢的组织与性能研究

对钛微合金化TRIP钢进行连续冷却转变曲线的测定,分析轧制与冷却工艺对其组织与性能的影响。结果表明:实验钢的奥氏体/铁素体、奥氏体/马氏体相变点分别在500~650℃和450℃左右;组织由铁素体/贝氏体及少量残余奥氏体组成;随着终轧温度的升高,实验钢的屈服强度和抗拉强度有所降低;随着空冷结束温度的降低,实验钢的屈服强度降低;当终轧温度和空冷结束温度分别为796℃和722℃时,实验钢的屈服强度,抗拉强度和强塑积分别为661,888MPa和25042MPa·%,其对应组织为细小的铁素体及板条贝氏体,铁素体基体上存在大量细小的析出物。     

热处理对TP347H钢组织结构及力学性能的影响

本文通过800--900℃的加速老化试验,研究热处理过程中TP347H钢的组织结构及力学性能的变化特征。结果表明：800℃,58h热处理,原奥氏体晶粒尺寸稳定,碳化物颗粒在晶界及晶内弥散析出;900℃,5．5h高温热处理后,析出碳化物聚集长大,导致晶界宽化。经900℃,5．5h高温处理后,TP347H钢仍为韧窝聚集型断裂,但断裂面相对平整,韧窝细而浅,且沿基体晶界有二次裂纹扩展。上述组织结构的变化导致热处理过程中TP347H钢的强度持续降低,而塑性先增加,后降低。     

Fe-26Mn-6A1-1C钢组织性能的研究

本文对Fe-26Mn-6A1-1C钢的力学性能及微观组织进行了分析。研究结果表明,该成分的高锰钢层错能为60mJ／m^2。,固溶态的屈服强度为450MPa,抗拉强度为780MPa,伸长率为58％,并呈连续屈服。在变形过程中,不发生相变。当变形程度低于30％时,实验钢的主要变形机制是位错滑移,并形成了亚结构,不发生显著的TWIP（twinning induced plasticity）效应。     

轧后冷却速率对14CrMoR钢板热处理后显微组织和力学性能的影响

首先对14CrMoR钢进行了轧制后不同冷却速率的冷却,然后进行了相同工艺的正火+回火热处理,研究了轧后冷却速率对14CrMoR钢板热处理后显微组织和力学性能的影响。结果表明:轧后冷却速率越小,钢板热处理后的各类显微组织越细小,珠光体和回火贝氏体组织的分布越均匀,综合力学性能也越好。     

Microstructures and Toughness of Weld Metal of Ultrafine Grained Ferritic Steel by Laser Welding

3 mm thick 400 MPa grade ultrafine grained ferritic steel plates were bead-on-plate welded by CO2 laser with heat input of 120～480 J/mm. The microstructures of the weld metal mainly consist of bainite, which form is lower bainite plates or polygonal ferrite containing quantities of dispersed cementite particles, mixed with a few of low carbon martensite laths or ferrite, depending on the heat input. The hardness and the tensile strength of the weld metal are higher than those of the base metal, and monotonously increase as the heat input decreases. No softened zone exists inheat affected zone (HAZ). Compared with the base metal, although the grains of laser weld are much larger, the toughness of the weld metal is higher within a large range of heat input. Furthermore, as the heat input increases, the toughness of the weld metal rises to a maximum value, at which point the percentage of lower bainite is the highest, and then drops.     

Microstructures and Toughness of Weld Metai of Ultrafine Grained Ferritic Steel by Laser Welding

3 mm thick 400 MPa grade ultrafine grained ferritic steel plates were bead-on-plate welded by CO2 laser with heat input of 120-480 J/mm. The microstructures of the weld metal mainly consist of bainite, which form is lower bainite plates or polygonal ferrite containing quantities of dispersed cementite particles, mixed with a few of low carbon martensite laths or ferrite, depending on the heat input. The hardness and the tensile strength of the weld metal are higher than those of the base metal, and monotonously increase as the heat input decreases. No softened zone exists in heat affected zone (HAZ). Compared with the base metal, although the grains of laser weld are much larger, the toughness of the weld metal is higher within a large range of heat input. Furthermore, as the heat input increases, the toughness of the weld metal rises to a maximum value, at which point the percentage of lower bainite is the highest, and then drops.     

针状铁素体钢的组织类型及对性能的影响

透射电镜下针状铁素体组织典型形貌为非常细微的亚结构、高密度的位错,应用透射电镜(TEM)原位拉伸、扫描电镜(SEM)原位拉伸,对F40船体结构钢的塑性变形与裂纹扩展的动态过程进行了动态观察,同时对F40钢低温下冲击断口形貌进行了详细的研究,结果表明,针状铁素体组织具有良好的抗塑性变形及阻止裂纹扩展的性能。     

Correlation between Microstructures and Yield Strength of a High Strength Enameling Steel

Numerical estimates of the components of yield strength of a high strength Fe-C-Mn-P-N-Si enameling steel were determined using empirical relationships between microstructure and yield strength. Results are reported for both the hot rolled (HR) and cold rolled (CR) forms before and after simulating an enamel-fire anneal (EFA). To determine the solubilities of alloying elements, thermodynamic calculations were performed in combination with the considerations of process conditions and the element diffusivities. The results show that the main solid solution strengtheners were the elements Mn, Si, and P, while the elements C and N were nearly completely tied up as precipitates. The yield strength reduction, due to the EFA, resulted primarily from an increase in grain size and a decrease in dislocation density, and the EFA appeared to have a negligible effect on the element solubilities.     

Microstructures of an Ultrafine Grained SS400 Steel in an Industrial Scale

The microstructures of a SS400 steel after thermomechanical control process（TMCP） in an industrial production were observed by optical microscope,scanning electron microscope（SEM） and transmission electron microscope（TEM）.The results indicated that the size of ferrite grains was 4-5μm,and transmission of ferrite was around 70%.The types of the ultrafine ferrite grains were analyzed and the strengthening mechanisms were discussed.The results show that the ultrafine ferrite grains came from three processes,i.e.deformation induced ferrite transformation（DIFT）.dynamic recrystallization of ferrite and accelerated cooling process.The increase in the strength of the material was mainly due to the grain refining.     

16Mn钢轧后控制冷却的贝氏体组织与性能

研究了１６Ｍｎ钢轧后会冷却工艺对贝氏体组织与性能影响，结果表明，采取适当的控冷工艺所得到细化铁素体和粒状贝氏体组织，可使１６Ｍｎ钢获得良好手强韧性配合，文中还对１６Ｍｎ钢轧后控冷所产生的贝氏体组织进行了分析。