异种金属材料焊接性的研究：HSn62—1与1Cr18Ni9Ti焊接铜渗透裂纹

本文是在冷却器HSn62—1黄铜与1Cr18Ni9Ti奥氏体不锈钢熔—钎焊(Welding—braze)工艺试验的基础上,采用铜合金焊丝对奥氏体不锈钢的焊接中产生铜渗透裂纹进行了机理的研究。通过熔一钎焊的TIG工艺大量试验数据表明,液态铜对奥氏体不锈钢润湿、渗透,在焊接应力作用下,沿晶界渗透扩展而开裂,并且在裂纹中充满了液态铜。由于液态铜使晶界表面能明显降低,同时对裂纹尖端壁面产生一种附加压力,促使液态铜沿晶界加速扩展,形成奥氏体不锈钢液态金属脆化而导致铜的渗透裂纹。 本试验采用七种钢合金焊丝进行熔一钎焊的TIG最佳工艺试验,提出了适用的焊丝,指明了产生铜渗透裂纹的基本规律,为完善异种金属焊接提供了理论依据。     

Microstructural morphology of the semi-solid high carbon steel T12 before and after rheo-rolling

The semi-solid high carbon steel T12 was rolled in a closed box groove under a certain condition by the rheo-rolling equipment, and the microstructural morphology of the semi-solid T12 before and after deformation was investigated by optical microscope to analyze and summarize the microstructure evolution law of T12 deformed in semi-solid state. The experiment results show that the grain shape before deformation of the semi-solid T12 steel displays globule or ellipse by the electromagnetic stirring,the distribution of solid and liquid phases is homogeneous. But the microstructure of semi-solid product after rheo-rolling exhibits macrosegregation that the distribution of liquid and solid phases changes, the liquid phases divorce from the solid phases. In the transverse section, most of the solid phases get together in the center of the specimen, the liquid phases flow to the surface or the edge of the specimen, and the grains occur plastic deformation while reduction increased. In longitudinal section, the middle microstructure of the specimen is more homogeneous than that at the head or tail, the head microstructure is similar to the tail and the size of the grains is not homogeneous.     

铝合金与奥氏体不锈钢的火焰钎焊

通过火焰钎焊的方法,实现铝合金（LF6）与奥氏体不锈钢（1Cr18Ni9Ti）的焊接．首先在不锈钢的表面热浸镀一层ZL102铝合金,然后采用搭接的形式对热浸镀层和铝合金进行焊接,并分析了焊接接头的微观组织和拉伸性能．试验结果表明,采用火焰钎焊的方法能够获得优质的焊接接头,但热浸镀层的结合强度低于母材、钎缝的强度．     

磷酸料浆泵叶轮用新型铁素体不锈钢的研制

研制了磷酸料浆泵叶轮用的一种新型铁素体不锈钢，探讨新型钢的合金成分设计，熔炼与热处理工艺设计，显微组织及性能，新型铁素体不锈钢含铬量，含碳量较高，其中Cr w%:26.0%-32.0%,CW%:0.4%-1.2%，最佳热处理工艺为800－900℃固溶化处理。挂片试验结果表明，新型铁素体不锈钢钢较以往的奥氏体不锈钢在磷酸料浆中具有更长的使用寿命，具有良好的耐磨性，耐腐蚀性。     

薄板异种钢焊接的研究

本文以薄型异种钢焊接作为研究对象,通过对焊接接头的各种试验和金相观察,来验证15CrMo与1Cr18Ni9Ti的可焊性,并提出了合理的工艺要点。     

Ratio of Fe-Al compound at interface of steel-backed Al-graphite semi-solid bonding plate

The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interfacial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The relationship between the ratio of Fe-Al compound at interface and bonding parameters (such as preheat temperature of steel plate, solid fraction of Al-7graphite slurry and rolling speed) was established by artificial neural networks perfectly. The results show that when the bonding parameters are 516 ℃ for preheat temperature of steel plate, 32.5% for solid fraction of Al-7graphite slurry and 12 mm/s for rolling speed, the reasonable ratio of Fe-Al compound corresponding to the largest interfacial shear strength of bonding plate is obtained to be 70.1%. This reasonable ratio of Fe-Al compound is a quantitative criterion of interfacial embrittlement, namely, when the ratio of Fe-Al compound at interface is larger than 70.1%, interfacial embrittlement will occur.     

三种不锈钢在含Cl^—衣康酸介质中的腐蚀行为

研究了３种不锈钢在衣康酸／氯化钠水溶液中的腐蚀和电化学特性并探讨了介质组成和温度的影响。结果表明,在一定范围内,随衣康酸浓度,氯化钠浓度和温芳的提高,不锈钢的腐蚀速率、致钝电流密度和维钝电流密度也有所增大,不锈钢的点蚀电位与衣康酸介质中Ｃｌ＾－浓度的对数间存在线性关系;     

18—8不锈钢钝化膜的光电化学研究

本文研究了18—8不锈钢钝化膜在硼酸/硼酸钠溶液中的光电化学特性,并和相同条件F纯铁、铬、镍以及铁铬合金钝化膜的光电化学行为进行了比较。结果指出,不锈钢钝化膜主要由Cr_2O_3和Fe_2O_3的固溶体组成,并具有非晶态n型半导体特性。其平带电位为-0.30V(SCE),禁带宽度为2.1eV。     

轧制及退火工艺对301B不锈弹簧钢力学性能影响分析

针对高硬不锈钢用作弹簧时弹性不足、疲劳寿命短等问题,本文结合现场实际生产,以301B奥氏体不锈钢带为研究对象,通过轧制工艺和热处理工艺优化,对其进行了拉伸试验和硬度测试。结果表明,增加变形率,采用低轧制油温度和低轧制速度的轧制工艺,并在冷轧后进行一次400℃低温去应力退火,可以提高带材强度和硬度。同时也说明,适当的轧制工艺和热处理工艺可以改善不锈弹簧钢带的力学性能,从而提高弹簧的弹性极限和疲劳极限。     

凝胶注模成型制备多孔NiTi合金工艺研究

以甲基丙烯酸羟乙酯为单体、油酸为分散剂,采用凝胶注模成型工艺制备NiTi形状记忆合金生坯,经1 050℃下真空保温6 h获得多孔NiTi形状记忆合金。研究发现,随着固相含量的增加,浆料黏度上升,当固相含量为43%时其流动性已无法满足注模的需求;当固相含量为43%的浆料加入质量分数为1%的油酸分散剂并经过40 min的球磨处理后,其流动性得到了改善并能够满足注模需求;烧结体晶粒发育良好,合金中除了NiTi相外还有少量的Ni3Ti和Ni2Ti等杂质相。     

Performance of Semi-solid Slurry Produced by Twin-screw Stirring Mixer and Rheo-diecasting Process of AZ91D Alloy

The microstructure of semi-solid slurry of AZ91D alloy, which was produced by twin-screw stirring mixer under the different parameters, was investigated. Rheoforming by cold chamber die casting process was performed thereafter. The results indicate that with decreasing of the barrel temperature of the mixer and the pouring temperature of molten Mg alloy, the solid fraction of semi-solid slurry increases and the size of non-den-dritic grains becomes smaller. While the shear rate increases, the solid fraction of semi-solid slurry decreases. The tensile strength and elongation of metal rheoformed by die casting are higher by about 37% and 44% respectively than those produced by conventional liquid die casting.     

Microstructural formation of semi-solid AZ91D alloy stirred by electromagnetic field

With the help of an electromagnetic stirring device, alloy melt quenching and EBSD (electron back scatter diffraction)analysis technology, the microstructure of the semi-solid AZ91D magnesium alloy slurry stirred by rotational electromagnetic field under different stirring power conditions has been studied. The results show that the size of primary α-Mg phase is reduced obviously when the solidifying alloy melt is stirred by rotational electromagnetic field, moreover, the primary α-Mg grains are changed to fine rosette grains or spherical grains which are proved to belong to the different grains in three-dimension by the EBSD analysis technology. The results also show that the stirring power is an important processing parameter in the preparation of the semi-solid AZ91D magnesium alloy slurry. The larger the stirring power, the finer the primary α-Mg grains, the less the rosette primary α-Mg grains, and the more the spherical primary α-Mg grains. Theoretical analysis indicates that a stronger flow motion leads to a more even temperature field and solute field and a stronger man-made temperature fluctuation in the alloy melt so that the specially fine rosette and/or spherical primary α-Mg grains are formed in the semi-solid AZ91D magnesium alloy slurry.     

Semi—solid Processing of Steel—Al—7 Graphite BInding Plate

The bonding of steel plate to Al-7 graphite slurry was studied for the first time.The relationship model about preheat temperature of steel plate,solid fiaction of Al-7 graphite slurry,rolling speed and nterfacial shear strength of bonding plate could be established by artificial neural networks perfectly.This model could be optimized with a genetic algorthm.The optimum bonding parameters are :516℃ for preheat temperature of steel plate,32.5% for solid fraction of Al-7 graphite slurry and 12mm/s for rolling speed,and the largest interfacial shear strength of bonding plate is 70.6MPa.     

5Cr15MoV马氏体不锈钢冷轧工艺研究

5Cr15MoV马氏体不锈钢宽带材(>1 200mm)的冷轧目前在国内尚属空白,研究其冷轧及轧后热处理工艺对产品结构优化及拓宽市场有着极其重要的意义.该钢种热轧态为马氏体组织,边部碳化物析出不均,具有硬度高、塑性差的特点,冷轧前对材料进行均值化热处理,改善了组织形态,可以有效地防止边裂;经过试制,在森吉米尔廿辊轧机上采用小张力、小压下且轧制速度在100m/min以下的轧制方式,能够顺利完成冷轧;轧后冷连续退火,板温控制在700～750℃,卷取采用小张力,避免出现180°以上折弯,以免发生断带的危险.     

低温氮化316奥氏体不锈钢在H2S环境下的静态腐蚀行为

为研究低温液体氮化奥氏体不锈钢在H₂S环境下的静态腐蚀机理,在430 ℃对316奥氏体不锈钢低温液体氮化8 h。模拟H₂S腐蚀环境,通过X射线衍射分析仪(XRD)、扫描电子显微镜(SEM)、分析天平、EPMA电子探针、X射线光电子能谱衍射仪研究低温液体氮化对奥氏体不锈钢在H₂S腐蚀环境下的静态腐蚀行为。结果表明,在静态腐蚀条件下,低温氮化后奥氏体不锈钢表面形成的含氮过饱和扩展奥氏体层(S-相)能够有效地阻止腐蚀介质向材料基体浸入,使得材料的腐蚀失重下降了34%,减缓了材料的腐蚀程度,显著提高了材料的表面性能。     

薄壁1Cr18Ni9Ti奥氏体不锈钢的焊接试验

采用钨极氩弧焊的方法,对0.8 mm厚的1Cr18Ni9Ti奥氏体型不锈钢板实施焊接,并通LOM,SEM方法对焊接接头组织及断口形貌进行观察及分析;利用显微硬度计、电子万能拉伸机测量了焊接接头的力学性能.结果表明,通过手工钨极氩弧焊,采用直流正接接法(焊接电流为20 A,焊接速度为20 m/h)能够获得外观平整、组织均匀、力学性能满足要求的焊接接头.     

An active control study of the 1Cr18Ni9 steel plate multipoint excitation

A multipoint excitation experiment system of the 1Cr18Ni9 steel plate-pipe network as the main vibration body was established,which used transient flow produced by the wave exciter to excite the 1Cr18Ni9 steel plate-pipe network to vibrate.The experimental results show that the 1Cr18Ni9 steel plate vibrates in three dimensions.The vibrations of the particles of the steel plate distributing along the pipe’s axial have phase differences and take place near the cylinder side first.Therefore,it is a multipoint vibration mode.The amplitude of the 1Cr18Ni9 steel plate increases as the system pressure increases and decreases as the wave exciter’s frequency decreases.The vibration intensity of the particles of the 1Cr18Ni9 steel plate close to the cylinder is the strongest and the amplitude is the highest in Y direction at a given system frequency.The vibration intensity of the particles close to the wave exciter is the strongest and the amplitude is the smallest in Z direction at a given system pressure.     

倾斜板长度及角度对9Cr18半固态坯料组织的影响

为了考察倾斜板参数对9Cr18半固态坯料组织的影响,进而为其触变成形提供微观组织基础,采用自制的波浪形倾斜板制备9Cr18半固态坯料,取样分析了坯料心部的金相组织.结果表明:随倾斜板长度从350 mm增加到840 mm,初生晶粒的等效直径从53.4μm减小到44.9μm,而形状因子从0.82略微提高到0.84;长度增大到595mm后,初生晶粒的形貌变化不明显.在倾斜板倾斜角度为35°~55°的范围内,随倾斜板角度增加,由于搅拌时间不足,初生晶粒的等效直径从50.5μm增大到70.8μm,而形状因子变小,从0.83下降到0.75.脱模淬火坯料比空冷坯料有更细小圆整的初生晶粒.     

不锈钢AOD精炼过程数学模拟的研究:模型的应用

以文献[1]中提出的数学模型处理了奥氏体型不锈钢的AOD精炼过程,并以在18tAOD炉中生产1Cr18Ni9型钢得到的32炉数据作了检验,模型估计结果与实测值相符,该模型可为不锈钢AOD过程的工艺优化和在线实时控制提供有用的信息和可靠的基础。     

Grain refining of flange plate for welded H section steel made under asynchronous rolling condition

Asynchronous rolling technology was adopted for the accumulated ten passes cold rolling, flange plate steel, and for welded H section steel, respectively. The metallographic microstructure analysis, tensile test and annealing test were carried out for cold rolled pieces; thus the ratio of length to width of grain, tensile strength, relationship between the grain size and asynchronous rolling process parameters after annealing can be obtained. The experimental results show that the relationship between the asynchronous rolling and the shearing deformation of rolled pieces can make a reasonable interpretation of the mechanism that asynchronous rolling may improve the strain accumulated energy of rolled pieces and the strength of flange plate steel. This paper provides a theoretical basis for the application of asynchronous rolling in improving the strength of flange plate steel.