热处理和磨削工艺对渗碳淬火汽车齿轮残余应力的影响

研究了渗碳热处理过程中淬火冷却和回火状况以及磨削加工对渗碳淬火汽车齿轮表面残余应力的影响.研究表明,充分淬火冷却有利于提高表面残余压应力,正确的磨削工艺不改变残余应力的分布,但过多的磨削热会导致在次表层产生高的拉应力.     

State of the Art Treatment of Non-Ferrous Castings 3-in-1 Heat Treatment Systems Combine Foundry Processes

The interior of a high-pressure die-casting is of an unsatisfactory quality. Engine blocks made with this die casting process show lower specific engine performance. Pressure die-casting can hardly be heat treated for obvious reasons PSM (Precision Sand Molds) process uses sand and organic binder to generate a mold and even allows the manufacturing of complex diesel engine blocks in aluminum alloys. Combined technologies are available for semi-permanent mold castings with cores and castings made in Precision Sand Molds with organic binders. Castings are placed into the special heat treatment furnace immediately after pouting without the operations in stand alone machinery. This patented Sand Lion^R 3-in-1 technology processes hot castings and carries out three (3) foundry processes simultaneously in one (1) automated machine: 1) De-coring and sand removal; 2) Thermal sand reclamation; 3) Solution heat treatment of castings. The combination of several main casting processes is reflected in significant reductions of energy consumption, of production costs, and improving the quality of the castings. Audits in foundries using the 3-in-1 process showed an average reduction in production costs of more than 30%.     

改善热处理淬火油冷却特性的方法

通过对热处理淬火油冷却特性的试验分析,找出了改善一重集团公司热处理厂现有淬火油冷却特性的方法为按适当比例添加68号标准机油。解决了热处理产品淬火质量不稳定的问题,并节约了大量的成本。     

冷轧15钢的高压热处理研究

对原始组织为马氏体的冷轧15钢在CS-IB型六面顶压机上进行了高压热处理,测量试样的维氏硬度。采用X射线和TEM对其晶体结构和组织形貌进行了分析。实验结果表明:试样在6GPa实验压力下于350℃发生了回复;450￣650℃发生了再结晶;750￣850℃发生了马氏体相变,产物为具有体心立方结构的针状马氏体和具有密排六方结构的网格状马氏体。伴随组织的变化,试样硬度先升高后降低再升高。     

Annealing behavior of rolled AZ31 alloy sheet

The annealed microstructures of the rolled AZ31 alloy sheets were examined by using light optical microscopy. The mechanical properties were measured by tensile testing, with their crystal orientations analyzed by X-ray diffraction （XRD）. After the annealing treatment, the elongated grains were transformed to equiaxed grains with uniform and homogeneous structures. The changes of microstructure decreased the yield strength and enhanced the elongation. The analysis of XRD shows that the AZ31 alloy sheet possesses intense basal-texture, which is weakened during the recrystallization while reinforced during the grain growth. The intense basal-texture induces low ductility, which hence makes the further rolling more difficult. The results indicate that the optimum annealing treatment during AZ31 alloys sheet rolling is at about 300 ℃ for 60-120 min.     

缓蚀阻垢剂的筛选及工业应用

针对现场循环冷却水的水质情况，研究了一种适用于循环冷却水的缓蚀阻垢剂配方，通过正交试验筛选出了一组最佳的浓度，使用该配方的缓蚀率达到82．56％。经静态阻垢试验和缓蚀评定试验分析，结果表明该配方有良好的缓蚀阻垢性能。当药剂配方浓度达50mg／L时，其缓蚀率和阻垢率均达到90％以上。在现场循环冷却水系统的应用中，对改善循环水水质也有很好的效果。     

阻燃镁合金AZ91D的研究

研究了通过添加铍，可得到直接暴露在大气中熔炼的镁合金AZ91D。通过金相组织观察发现：当铍的含量达到0.015%时，合金的晶粒度最好，而且具有很好的阻燃性能；同时研究了采用不同的变质剂AZ91D合金进行变质处理。实验结果表明：变质处理的AZ91D合金，组织明显细化，尤其是时效处理后，其力学性能得以大幅度提高，拓宽了合金的使用范围。     

Φ508mm×9.5mm L450MB钢级ERW管线管的试制

焊缝冲击功低且不稳定是ERW管线管生产的一大技术难点。针对高钢级L450MB焊管存在焊缝冲击功不稳定的情况,宝山钢铁股份有限公司宝钢分公司钢管厂采取降低焊接速度、调整热处理工艺的技术方案,试制出焊缝冲击韧性符合标准要求的L450MB钢级ERW管线管。     

真空热处理对Ti6Al4V基体/NiCrAlY涂层体系组织结构及元素扩散行为的影响

采用电弧离子镀(AIP)技术在Ti6Al4V基体表面沉积制备了NiCrAlY涂层. 通过金相观察(OM)、扫描电镜(SEM)与能谱(EDS)分析、 X射线衍射(XRD)分析以及显微硬度测试, 研究了真空热处理对NiCrAlY涂层组织性能的影响, 讨论了Ti6Al4V基体/NiCrAlY涂层界面元素扩散规律. 结果表明: 700.℃真空热处理后, NiCrAlY涂层中开始析出γ′-Ni3Al相, 这提高了涂层的表面硬度; 在700.℃温度下, Ti6Al4V基体/NiCrAlY涂层界面由外至内出现Ni3(Al,Ti)、 TiNi和Ti2Ni中间化合物层, 并随着温度提高, 界面处中间化合物层增厚; 700.℃时, 主要发生了镍、钛元素的扩散, 铬元素在870.℃开始发生扩散. 当温度提高到950.℃后, 由于镍元素大量向Ti6Al4V基体扩散引起涂层的退化失效.     

Isothermal oxidation behavior of FeCo–2V intermetallic alloy

Isothermal oxidation behavior and the nature of oxide layer formed during oxidation of FeCo–2V alloy were characterized in the temperature range of 500–600 °C. Oxidation kinetics of the alloy follows a parabolic rate law. SEM and XRD studies indicate the formation of an iron rich outer oxide layer and an inner solute rich layer containing cobalt and vanadium rich oxides. The oxidation mechanism of the FeCo–2V alloy is similar to that of low alloy steels. During the initial stages, preferential oxidation of iron and cobalt occurs at the alloy surface and leads to the formation of a solute rich inner layer. Continued oxidation occurs through oxidation of iron and cobalt at the outer layer and internal oxidation of inner layer. The iron rich oxide layer formed at the surface on oxidation of FeCo alloy is semi-conducting in nature and may not provide the necessary insulating barrier required at the surface to minimize eddy current losses during A.C. applications.