热加工工艺对钛-钢复合板界面力学性能和显微组织的影响

研究了热加工工艺对钛-钢复合板界面力学性能和显微组织的影响.测试了在A,B,C,D 4种温度下热轧复合板界面的力学性能,用金相显微镜及扫描电镜观察了界面显微组织并分析了界面的成分.结果表明,在A,B 2种温度下轧制的钛-钢复合板界面机械性能良好,延伸率高,其剪切强度不但可保持坯料原有的水平,甚至还略有增加.在C,D 2种温度下轧制的钛-钢复合板界面机械性能相对较低,延伸率较高,但剪切强度要比爆炸复合坯料低,尤其是D加热温度,轧制后界面剪切强度急剧下降.热轧的终轧温度也是影响钛-钢复合板界面结合性能的重要因素.在低于相转变温度的合适温区热轧,且终轧温度合适,获得的钛-钢复合板结合界面无爆炸波纹,没有污染,生产的脆性化合物极细小,组织类同于钛材完全退火的等轴组织.     

冷轧成形钛/钢层状复合板界面结合强度的影响因素EI北大核心CSCD

采用冷轧复合法制备钛/钢层状复合板,研究轧制压下率、轧制道次、表面粗糙度、原材料状态和轧制速率对钛/钢层状复合板界面结合强度的影响。结果表明:界面作用力和轧制力对界面的作用时间是影响钛/钢层状复合板界面结合强度的主要因素。轧制压下率、表面粗糙度和原材料状态通过影响界面作用力来影响钛/钢层状复合板的界面结合强度;轧制速率通过影响轧制力对界面的作用时间来影响钛/钢层状复合板的界面结合强度;钛/钢层状复合板的冷轧复合效果与轧制道次无关,只有单道次轧制压下率超过临界轧制压下率时,才能实现冷轧复合。     

冷轧成形钛/钢层状复合板界面结合强度的影响因素

采用冷轧复合法制备钛/钢层状复合板,研究轧制压下率、轧制道次、表面粗糙度、原材料状态和轧制速率对钛/钢层状复合板界面结合强度的影响。结果表明:界面作用力和轧制力对界面的作用时间是影响钛/钢层状复合板界面结合强度的主要因素。轧制压下率、表面粗糙度和原材料状态通过影响界面作用力来影响钛/钢层状复合板的界面结合强度;轧制速率通过影响轧制力对界面的作用时间来影响钛/钢层状复合板的界面结合强度;钛/钢层状复合板的冷轧复合效果与轧制道次无关,只有单道次轧制压下率超过临界轧制压下率时,才能实现冷轧复合。     

钛网添加对镁/铝复合板微观组织和力学性能影响研究

目的 有效抑制镁/铝复合板界面处金属间化合物的形成。以钛网为中间金属夹层,研究它对镁/铝复合板微观组织和力学性能的影响。方法 利用复合轧制技术制备以钛网为中间金属夹层的镁/铝-钛复合板,采用扫描电子显微镜(SEM)、电子背散射衍射仪(EBSD)、万能试验机等对复合板退火前后的微观组织和力学性能进行表征和分析,系统研究中间层钛网对轧制态和退火态复合板微观组织、织构、拉伸性能、界面结合强度的影响规律。结果 中间层钛网均匀分布在镁/铝-钛复合板界面处,钛网的添加能有效抑制复合板退火过程中镁-铝金属间化合物的连续生长,减少金属间化合物的数量。与镁/铝复合板相比,钛网的添加对轧制态和退火态复合板中镁层和铝层的平均晶粒尺寸和织构类型的影响较小。与镁/铝复合板相比,钛网的添加降低了轧制态复合板的界面剪切强度和延伸率,但极大提升了退火态复合板的界面剪切强度、拉伸强度和延伸率。结论 中间层钛网的添加可有效减少复合板界面处金属间化合物的数量,提升退火态复合板的综合力学性能。     

大面积、薄覆层钛/钢复合板爆炸-轧制工艺研究

探索了大面积、薄覆层钛/钢复合板生产工艺.分析了不同的轧制温度下爆炸-轧制钛/钢复合板的性能和组织.结果表明,配制低爆速混合炸药,在覆层与基层之间增加一层纯铁过渡层,采用合适的爆炸复合工艺制得轧板复合板坯,再在适当的热轧温度下轧制,可获面积超过35 m2、覆层厚度≤2.0 mm的钛/钢双金属复合板且各项性能指标符合国家标准要求;此项研究填补了国内空白,满足了市场需求.     

铝/钛/铝三层复合板热轧工艺及微观组织研究

钛/铝层状复合材料具有两种材料优异的特性,能够满足一些特殊工程需要。开发了热轧复合技术,成功制备了铝(1100)/钛(TA2)/铝(1100)三层复合板。研究了复合板轧制过程中的关键轧制技术参数(临界压下率和轧制复合工艺条件)。利用光学显微镜和SEM观察了钛/铝复合板及结合界面形貌,分析了不同退火温度对复合板力学性能的影响。基于实验结果,描述了影响复合板质量和有助于提高复合板结合强度的关键工艺过程。     

层状镁/铝复合板轧制工艺研究进展

镁/铝复合板具有密度小、比强度高和耐腐蚀性好等优点,广泛应用于航空航天、汽车制造等领域.轧制法是目前生产镁/铝复合板最为广泛的一种方法,该法设备简单、操作容易、成本低廉.介绍了普通轧制法、异步轧制法、爆炸+轧制法、累积叠轧法、固-液铸轧法、波-平轧制法6种轧制工艺,以及这些工艺在制备镁/铝复合板时的优缺点.波-平轧制工艺可以提高复合板的平直度,有利于板材后续加工成形.也研究了轧制温度、轧制压下率、轧制速度、轧后退火处理对镁/铝复合板力学性能的影响,镁/铝界面金属间化合物的形成因素,以及化合物层厚度对镁/铝复合板力学性能的影响.     

异步轧制对钢/铝复合板组织与性能的影响

采用金相显微镜、扫描电镜及材料拉伸试验机等研究了异步轧制工艺制备的钢/铝复合板的组织与性能,探讨了异步速比对复合板界面剪切强度的影响。结果表明,异步轧制工艺可在30%的临界压下率下实现钢/铝的有效初结合,板材的初结合强度高于同步轧制样品。复合板的界面剪切强度随异步速比的增加先增大后减小,最佳的异步速比为1.2～1.25。异步轧制过程可实现钢基体粗大柱状晶的破碎与晶粒细化,轧后的复合板在450℃退火1h后即可以使钢基体获得理想的软化效果,克服了同步轧制样品在温度超过500℃退火时界面易生成脆性金属间化合物的难题。复合板的反复弯曲次数可达10次。     

铝合金-钢爆炸焊接装药量与界面性能的关系(英文)

通过设计不同的爆炸焊接工艺参数爆炸复合了铝合金-钢爆炸复合板,并对复合板的界面性能进行了显微分析和力学性能测试,探讨了爆炸焊接装药量对复合板界面性能的影响。结果表明:在铝合金-钢复合板的的结合界面产生了一层金属间化合物并且在化合物中产生了许多微裂纹。随着装药量的增加,界面化合物的厚度略有增加,其上微裂纹的的数量也有所增加。复合界面的剪切强度随着装药量的增加而有所降低。界面化合物对复合板强度产生不利影响,铝合金-钢爆炸焊接时应尽量采用小药量。     

退火工艺对铜包钢线界面扩散和结合强度的影响

采用双铜带压接法制备铜包钢线,研究了铜包钢线的退火热处理工艺,探讨了退火温度和时间对铜-钢复合界面扩散和结合强度的影响。结果表明,随着铜包钢线退火温度的升高和时间的延长,扩散层厚度增加,界面结合强度提高。与保温时间相比,退火温度对其影响较大。退火温度为750℃,保温2h后界面结合效果最佳,继续升高温度和延长时间,界面扩散层厚度和结合强度几乎不变。利用扩散方程计算Fe和Cu原子的扩散激活能和扩散常数,确定了扩散常数与退火温度的关系。综合考虑铜包钢线扩散层厚度与结合强度的关系及生产实际要求,得到铜包钢线的最佳退火工艺为750℃保温2h。     

爆炸焊接钛钢复合板结合强度超声检测评定

如何用超声的方法对钛钢复合板的结合强度进行分级评定,对钛钢复合板的使用有迫切现实需要。本文采用超声检测一次底波和钛钢界面回波的比值,与剪切强度进行比较研究,并分析了界面波纹和界面金相。实现用A型超声检测的方法对钛钢复合板进行分级评定。经过试验分析,20 lg(B1/S)的数值大于9时,爆炸钛钢复合板的剪切强度大于180 MPa。     

钛/钢多层爆炸焊接界面的实验研究

为探究膨化硝铵炸药作用下,厚度均为2 mm的钛(Ti)、钢板的最优爆炸焊接参数以及验证一种新的爆炸焊接试验方案,实验采取阶梯型多层基板的爆炸焊接试验方案,以控制药量和间距为变量,并将Ti板作为复板,同时对多层阶梯型钢基板进行爆炸焊接试验;利用金相显微镜对焊接复合板进行观察,并分析多层基板同时焊接的方案可行性以及不同实验参数对界面波形的影响。试验结果和分析表明:通过观察Ti/钢复合板界面波形呈正弦微波状且无明显过渡层,验证了新方案的可行性,同时突出了阶梯型多层基板的同时爆炸焊接方案,能够在单次试验下对比分析不同基复板间距情况下的焊接效果的能力;并经分析得出在单位面积装药为1.048 g/cm~2及装药间距范围为(9~11)mm时,能得到质量较佳的Ti/钢爆炸复合板。     

Effect of interfacial compounds on mechanical properties of titanium–steel vacuum roll-cladding plates

The titanium–steel clad plates were prepared by vacuum roll cladding. Ti–Fe compounds and TiC were observed at different cooling rates after rolling. Optical microscopy, electron microprobe analyser, X-ray diffraction and shear test studies were carried out to study the effect of Ti–Fe compounds and TiC on the ultimate microstructure and mechanical properties of titanium–steel clad plates. At a cooling rate of 6.2°C/min, TiC and Ti–Fe compounds seriously impacted the mechanical properties of the clad plate. At a cooling rate of 1.8°C/min, the thickness of the TiC layer was optimal much that the maximum shear strength of 296?MPa was obtained. At a cooling rate of 0.6°C/min, the thickness of the TiC layer was relatively thick, which affected the mechanical properties of clad plates.     

316L-Q345R不锈钢复合板性能评价

从微观组织和显微硬度两方面对真空热轧316L-Q345R不锈钢复合板试样性能进行评价。采用电子显微和能谱分析技术,对试样进行微观组织特征观察和成分含量测定,研究相结构及成分变化规律。通过硬度测试仪对复合板界面附近硬度进行测量,研究微观组织与硬度关系。结果表明:热轧后复合板Q345R侧显微组织以铁素体和珠光体为主,316L侧显微组织为单一奥氏体,一部分晶粒呈孪晶状态,Q345R低合金钢和316L不锈钢经过热轧可良好复合,复合界面平直;界面两侧元素存在扩散现象,不锈钢中Cr,Ni元素向低合金钢侧扩散,在界面形成富Cr,Ni薄层,低合金钢中C向不锈钢侧产生少量迁移;在复合界面处的硬度值较大,低合金钢侧远离界面位置复合板硬度与Q345R本身硬度值接近,而从界面到不锈钢侧硬度呈现先下降后上升至稳定的趋势。     

Influence of hot rolling and heat treatment on structure and properties of HSLA steel explosively clad with austenitic stainless steel

Abstract

The present work aims at studying structure–property correlations in an explosively clad HSLA steel with austenitic stainless steel of AISI 304L grade. The clad plate was subjected to hot rolling followed by a quenching and tempering treatment to achieve better mechanical properties in the base plate. Optical microscopy studies revealed that the interface between the two steels was wavy in the as clad plate and the waviness decreased substantially due to hot rolling. Subsequent heat treatment has not shown any significant effect either. The base plate had tempered martensite/bainite structure in as clad or heat treated conditions and ferrite-pearlite-bainite structure in hot rolled condition. The grains were finer and elongated near the interface. The stainless steel exhibited equiaxed grain structure in as clad, hot rolled or heat treated plates. Tensile properties and charpy impact energy of the base plate were lowered due to hot rolling and then increased substantially due to heat treatment. The microhardness was observed to be a maximum at the bond interface for all three conditions studied. The shear bond strength was the highest in the as clad condition and decreased for the rolled as well as heat treated conditions. Scanning electron microscopy fractography on shear bond specimens revealed the presence of predominantly equiaxed dimples with few regions of rubbed fracture. Quantitative electron probe microanalysis across the bond interface indicated linear change in concentrations of nickel, chromium and manganese between the levels appropriate to the clad layer and base metal.     

Weld overlay cladding of high strength low alloy steel with austenitic stainless steel – Structure and properties

The present work aims at studying structure–property correlations in a weld overlay clad high strength low alloy steel with austenitic stainless steel of American Institute for Steel and Iron (AISI) 347 grade. Optical microscopy studies revealed that the interface between the two steels was nearly flat. The base plate had ferrite plus bainite microstructure adjacent to the interface and tempered bainite/martensite structure away from the interface. Grain coarsening and decarburization were observed near the interface. The stainless steel exhibited austenite dendritic structure. Tensile strength, notch-tensile strength and charpy impact energy of the base plate were found to be higher than those for the interface. The microhardness was observed to be maximum on the clad layer near interface. The shear bond strength of the weld overlay-interface was higher than the shear strength of the base plate. Fractography was carried out using scanning electron microscope on tensile, notch-tensile and shear bond test specimens of the interface as well as shear test specimens of the base plate. It revealed the presence of predominantly dimpled rupture. Charpy impact specimens of the interface failed in mixed mode while impact specimens of the base plate failed in ductile mode. Electron probe microanalysis across the bond interface indicated linear change in concentrations of Cr, Ni, Mn, Cu, Mo, Nb and Si between the levels appropriate to the clad layer and base metal.     

Research on explosive welding of aluminum alloy to steel with dovetail grooves

In order to explore a new method for the explosive welding of aluminum alloy to steel, a 5083 aluminum alloy plate and a Q345 steel plate with dovetail grooves were respectively employed as the flyer and base plates. The parameters adopted in the explosive welding experiment were close to the lower limit of weldable window of 5083 aluminum alloy to Q345 steel. The bonding properties of 5083/Q345 clad plate were studied through mechanical performance tests and microstructure observations. The results showed that the aluminum alloy and steel plates were welded under the actions of metallurgical bonding and meshing of dovetail grooves. The tensile shear strength of 5083/Q345 clad plate met the requirements of the bonding strength of Al/Fe clad plate. The interfaces between aluminum alloy and the upper and lower surfaces of dovetail grooves were mainly welded through direct bonding, and discontinuous molten zone emerged in the local region; while the interface between aluminum alloy and the inclined surface of dovetail grooves was bonded by continuous molten layer. The brittle intermetallic compounds FeAl₂ and Al₅Fe₂ were generated at the bonding interfaces of 5083/Q345 clad plate. The fracture surface of the tensile specimen exhibited ductile and quasi-cleavage fractures.     

爆炸复合板与轧制复合板界面结构的研究

用透射电镜、扫描电镜和能谱仪等手段对爆炸和轧制复合板界面组织、相结构和成分变化进行了研究。结果发现爆炸复合是由周期性熔化和非熔化构成的波状复合面，它比轧制扩散复合形成的平面积多１／３左右。两种复合方式都有越过界面的元素扩散，爆炸态扩散范围在２５μｍ左右；轧制态Ｆｅ、Ｎｉ、Ｃｒ元素扩散范围在５０μｍ左右，碳元素越过纯Ｎｉ层向不锈钢侧的扩散范围为１００μｍ左右，在此区域发现沿晶界连续析出有Ｍ２３Ｃ６型碳化物。     

铂／钛复合板轧制工艺及结合机理研究

针对海港码头电化学保护用铂／钛阳极材料的特点，讨论了铂／钛爆炸复合板轧制以及经轧制后的组织、成份分布和性能的变化，以便为这种复合材料的实际应用提供依据。     

生产工艺对爆炸复合用钛板的影响研究

对比热轧和卷轧工艺技术,研究了不同生产方式对爆炸复合用钛板性能和组织的影响。结果表明:块式热轧生产钛板的效果最好,炉卷轧制方式次之,但其生产率和成品率高;少量添加回收料可批量生产合格的钛板,但伸长率的富裕量降低。因此,需要严格控制原料成分,并选择适宜的生产工艺方式,以确保钛板性能满足爆炸复合要求。