铝硅合金无毒精炼长效变质综合处理工艺及材料的研究

本文论述铝硅合金精炼、变质综合处理工艺的原理,对以锶、钠复合盐为基的SN310长效熔剂的主反应进行了化学热力学计算和动力学分析,测定了熔剂的发气量,简要叙述了熔剂的制作工艺及处理工艺。通过对精炼、变质效果的测定和炉气分析证明:SN310长效熔剂不但可以将精炼、变质两步工序合为一次处理,而且变质有效期达六小时,炉气中有害气体的含量远远低于国家标准。文中还对影响精炼、变质效果的因素及社会经济效益进行了分析和对比。     

高铬白口铸铁复合变质的作用

采用RE-A1-Bi-Mg对高铬白口铸铁进行复合变质。在炉内、炉外实行“二步法”处理并按变质合金异质形核的生核能大小设计分级处理的顺序，起到了控制碳化物的析出量和改善析出形态，净化铁液，净化晶界，细化晶粒等良好的变质效果。这些变化主要是复合变质所产生的动力学效应对其影响的结果。这种变质作用受制于复合变质在冶金处理过程中所应具备的相关的动力学条件。     

用NiO直接合金化制备高铬铸铁试验研究

通过以NiO代替Ni进行直接合金化、添加稀土复合变质剂,对中频炉制备高铬铸铁进行了工艺试验。从高铬铸铁化学成分设计,熔炼工艺、NiO及稀土变质剂的加入方法、热处理工艺等方面介绍了工艺优化后高铬铸铁的制备方法。以NiO代替Ni,Ni的收得率达到98.9%。采用该工艺制备的高铬铸铁铸态硬度HRC 58~59,热处理硬度HRC62.5~63.5。采用该工艺制备的高铬铸铁耐磨性能比高锰钢衬板耐磨性能提高2倍以上,生产成本降低9.1%~10.6%。     

熔模铸造条件下ZL111合金熔炼工艺

通过采用3种精炼剂对ZL111进行熔炼试验,并经9炉次熔炼和4炉次T6试验,确定回炉料加入量、精炼剂与变质剂加入量及工艺参数.获取熔模铸造条件下合格铸件的化学成分和力学性能指标值,为批量生产提供科学依据.     

熔模铸造条件下 ZL111熔炼工艺的研制

通过采用三种精炼剂对ZL111进行熔炼试验,并经9炉次熔炼和4炉次T6试验,确定回炉料加入量、精炼剂与变质剂加入量及工艺参数.获取熔模铸造条件下合格铸件的化学成分和机械性能指标值,为批量生产提供科学依据.     

中频炉如何保持较高炉龄

提高感应电炉坩埚的使用寿命是每一个铸造工作者追求的目标，对企业也将有重大意义。文章分别介绍了筑炉材料、筑炉工艺、烘炉工艺、用炉工艺对电炉坩埚使用寿命的影响，并探讨了如何提高炉子的使用寿命。     

亚共晶铝-硅合金的综合变质处理

本文研究不仅能细化显微组织,而且可细化宏观组织的综合变质处理方法。对AЛ2(相当于ZL102—译者)合金进行了试验,用通常工艺在CAT—0.25炉中熔炼,在BYO保温炉中加入六氯乙烷(0.3％加入量)精炼。然后按通常工艺进行变质处理(加入1.5％三元变质剂,成分是:45％NaCl;40％NaF     

高锰钢复合变质的作用及动力学条件

采用RE-Ca-Ti-Al对高锰钢进行复合变质.在炉内、炉外实行"二步法"处理并按变质合金异质形核的生核能大小设计分级处理的顺序,起到了控制碳化物的析出量和改善析出形态,净化钢液,净化晶界,细化晶粒等良好的变质效果.这些变化主要是复合变质所产生的动力学效应对其影响的结果.这种变质作用受制于复合变质在冶金处理过程中所应具备的相关的动力学条件.     

转炉炉龄提高后炉型控制的实践

简介了济钢第一炼钢厂在炉龄提高后的炉型控制状况；重点针对溅渣后炉型的变化，优化了溅渣护炉和砌炉工艺，改进了炉渣性质，进而提高了溅渣护炉效果和保持了合理炉型，保证了生产的稳定运行。该厂控制炉型的实践对炼钢生产有一定的指导意义。     

CX型长效无公害铝硅合金变质剂的应用

本文介绍了ＣＸ型长效无公害铝硅合金变质剂对ＺＬ１０８和ＺＬ１０４合金的变质效果。结果表明：该变质剂对铝硅合金有双重变质作用，可同时细化和改善初生硅和共晶硅形貌，且具有速效和持效作用，提高铝硅合金的力学性能和铸件的使用性能；该变质剂加入量少，变质工艺简便，处理时无烟雾、粉尘和刺激性气味，具有良好的技术经济效果。     

热轧复合刀片工艺改进

用传统工艺生产热轧复合刀片 ,存在复合线明显、镰刀弯、竹节裂纹、内应力强等缺陷 ;改进加热炉、轧机、活性烧结料及增加变形量后 ,产品缺陷消除 ,刀片寿命提高 1倍以上。     

真空液相活化烧结对金刚石孕镶体性能的影响

本文研究金刚石刀头真空热压烧结与普通热压烧结的烧结成型及结合性能。通过真空烧结采用含有强碳化物形成元素的低熔点预合金粉末作为粘结相，采用三点弯曲试验测试了普通热压烧结与真空液相活化烧结试样的抗弯强度，用SEM观察了断口金刚石表面的界面反应。结果表明，采用真空液相活化烧结使得钛元素在金刚石表面聚集，与碳原子形成碳化钛，提高了金刚石与基体金属的结合力以及基体自身的强度。切割实验表明真空液相活化烧结刀头锋利度及寿命明显提高。     

Numerical simulation on vacuum solution heat treatment and gas quenching process of a low rhenium-containing Ni-based single crystal turbine blade

Numerical heat-transfer and turbulent lfow model for an industrial high-pressure gas quenching vacuum furnace was established to simulate the heating, holding and gas fan quenching of a low rhenium-bearing Ni-based single crystal turbine blade. The mesh of simpliifed furnace model was built using ifnite volume method and the boundary conditions were set up according to the practical process. Simulation results show that the turbine blade geometry and the mutual shielding among blades have signiifcant inlfuence on the uniformity of the temperature distribution. The temperature distribution at sharp corner, thin wal and corner part is higher than that at thick wal part of blade during heating, and the isotherms show a toroidal line to the center of thick wal. The temperature of sheltered units is lower than that of the remaining part of blade. When there is no shelteration among multiple blades, the temperature distribution for al blades is almost identical. The lfuid velocity ifeld, temperature ifeld and cooling curves of the single and multiple turbine blades during gas fan quenching were also simulated. Modeling results indicate that the loading tray, free outlet and the location of turbine blades have important inlfuences on the lfow ifeld. The high-speed gas lfows out from the nozzle is divided by loading tray, and the free outlet enhanced the two vortex lfow at the end of the furnace door. The closer the blade is to the exhaust outlet and the nozzle, the greater the lfow velocity is and the more adequate the lfow is. The blade geometry has an effect on the cooling for single blade and multiple blades during gas fan quenching, and the effects in double layers differs from that in single layer. For single blade, the cooing rate at thin-waled part is lower than that at thick-waled part, the cooling rate at sharp corner is greater than that at tenon and blade platform, and the temperature at regions close to the internal position is decreased more slowly than that close to the surface. For multiple blades in single layer, the temperature at sharp corner or thin wal in the blade that close to the nozzles is much lower, and the temperature distribution of blades is almost paralel. The cooling rate inside the air current channel is lower than that of at the position near blade platform and tenon, and the effect of blade location to the nozzles on the temperature ifeld inside the blade is lower than that on the blade surface. For multiple blades in double layers, the lfow velocity is low, and the lfow is not uniform for blades in the second-layer due to the shielding of blades in the ifrst-layer. the cooling rate of blades in the second-layer is lower than that in the ifrst-layer. The cooling rate of blade close to the nozzles in the ifrst-layer is the higher than that of blade away from the nozzles in the second-layer, and the temperature distribution on blades in the same layer is almost paralel. The cooling rate in thin wal position of blade away from the nozzles is larger than that in tenon of the blade closer to the nozzles in the same layer. The cooling rate for blades in the second-layer is much lower both in thin wal and tenon for blades away from the nozzles.     

静叶片铸造工艺的正交试验研究

合金含量、精铸工艺参数（出炉温度、浇铸温度、模壳预热温度、保温时间、冷却方式）对叶片脆性问题存在一定的影响。为了消除静叶片的脆性断裂，采用正交试验对脆性问题进行了研究。结果表明，合金含量及工艺参数的交互作用对叶片脆性影响显著。     

Influence of platform position on stray grain nucleation in Ni-based single-crystal dummy blade clusters

Stray grains are the most severe of the solidification defects that occur in the industrial single-crystal blade preparation process. In this study, a single-crystal dummy blade cluster with different crystal orientations controlled by the seeding method was prepared, and the influence of the position of the circular platform (relative to the sample and furnace body) on stray grain nucleation was investigated. Results show that the microstructure of the circular platforms could be divided into the center, expansion, and stray grain regions. The inside of the circular platform facing the center of the cluster is more prone to stray grain formation than the outside of the circular platform facing the furnace body. With an increase in the distance between the circular platform and the bottom of the dummy blade cluster, the stray grain region expands, whereas the expansion region narrows. The stray grain is slightly aggravated with increase of the misorientation. Finally, the mechanism underlying the influence of platform position on the formation of stray grains in single-crystal dummy blade clusters is discussed based on the temperature evolution during directional solidification.

     

基于UG二次开发的单晶涡轮叶片浇注系统建模

单晶涡轮叶片的制备通常采用定向凝固技术在真空炉中进行,适用于单晶凝固模拟的有限元模型结构复杂,前处理难度大。针对此问题,基于UG二次开发实现了单晶涡轮叶片浇注系统的参数化建模,简化复杂浇注系统的设计工作,提高建模效率和准确性。参数化建模同时会自动消除浇注系统各部分的重合面,从而在网格剖分时避免交错面的产生,减少网格错误,节省前处理时间。     

基于DD5单晶高温合金制件的时效处理转炉试验

为验证DD5单晶高温合金制件时效处理工艺转入新引进国产真空炉是否满足工艺要求,同时与进口真空炉中完成时效处理后的试样进行对比以确认差异,特开展了时效处理工艺转炉试验。采用DD5单晶高温合金航空发动机涡轮叶片和试棒分别在新引进国产真空炉和进口真空炉中完成时效处理后,分别对叶片的宏观组织、微观组织和表面贫Cr层以及试棒的高温拉伸性能进行了测试与分析。结果表明:在时效处理阶段,国产真空炉与进口真空炉在参数控制能力相当,能够满足DD5单晶合金制件的时效处理要求,可替代进口真空炉完成时效处理。     

Numerical simulation and experimental verification of gravity and centrifugal investment casting low pressure turbine blades for high Nb–TiAl alloy

Gravity and centrifugal investment casting processes of low-pressure turbine blades with high Nb–TiAl alloy were simulated by Procast software. Actual blade components were poured by vacuum induction suspended furnace with Ar protection. The experimental verification indicated that the simulation results were in good agreement with the experimental results. Comparative results had shown that the surface of centrifugal casting blade was more complete than that of gravity casting one. In gravity casting process, molten metal filled the thinnest trailing edge at last, resulting in the generation of misrun defects. Furthermore, the shrinkage porosity and crack defects of gravity casting were much more and dispersive. The internal and external quality of centrifugal casting was much better than that of gravity casting. Microstructures from edge to center of gravity casting blade had no significant change. The microstructure for centrifugal casting blade is finer than that for gravity casting blade, however, a large number of dentritic γ segregation appeared in the blade edge of centrifugal casting, which resulted from the fast cooling rate of centrifugal casting surface.     

三峡水轮机不锈钢叶片的铸造

一重公司通过对钢包精炼炉进行真空氧脱碳(VOD)改造,成功地熔炼并浇铸出碳含量的质量分数在0.03%以下且气体含量很低的三峡水轮机用不锈钢叶片。所制叶片不论化学成分、冶金质量还是型线、尺寸均达到了设计要求。目前,该叶片经热处理及补焊后已用于三峡电厂第12号机组。     

三峡水轮机叶片用不锈钢的熔炼

一重公司通过对钢包精炼炉进行真空氧脱碳(VOD)改造(安装水冷氧枪和真空加料系统),成功地熔炼并浇铸出碳含量在0.03wt%以下且气体含量很低的三峡水轮机用不锈钢叶片。所制叶片不仅化学成分、冶金质量均达到了设计要求,而且比以往工艺降低生产成本约13%,技术经济效益十分可观。