Characterization of blasted austenitic stainless steel and its corrosion resistance

It is known that the corrosion resistance of stainless steel is deteriorated by blasting, but the reason for this deterioration is not clear. A blasted austenitic stainless steel plate (JIS-SUS304) has been characterized with comparison to the scraped and non-blasted specimens. The surface roughness of the blasted specimen is larger than that of materials finished with #180 paper. A martensite phase is formed in the surface layer of both blasted and scraped specimens. Compressive residual stress is generated in the blasted specimen and the maximum residual stress is formed at 50–100 μm from the surface. The corrosion potentials of the blasted specimen and subsequently solution treated specimen are lower than that of the non-blasted specimen. The passivation current densities of the blasted specimens are higher those of the non-blasted specimen. The blasted specimen and the subsequently solution treated specimen exhibit rust in 5% sodium chloride (NaCl) solution, while the non-blasted specimen and ground specimen do not rust in the solution. It is concluded that the deterioration of corrosion resistance of austenitic stainless steel through blasting is caused by the roughed morphology of the surface.     

Multidisciplinary optimization of gas-quenching process

Distortion as a result of the quenching process is predominantly due to the thermal gradient and phase transformations within the component. Compared with traditional liquid quenching, the thermal boundary conditions during gas quenching are relatively simple to control. By adjusting the gas-quenching furnace pressure, the flow speed, or the spray nozzle configuration, the heat-transfer coefficients can be designed in terms of both the component geometry and the quenching time. The purpose of this research is to apply the optimization methodology to design the gas-quenching process. The design objective is to minimize the distortion caused by quenching. Constraints on the average surface hardness, and its distribution and residual stress are imposed. The heat-transfer coefficients are used as design variables. DEFORM-HT is used to predict material response during quenching. The response surface method is used to obtain the analytical models of the objective function and constraints in terms of the design variables. Once the response surfaces of the objective and constraints are obtained, they are used to search for the optimum heat-transfer coefficients. This process is then used instead of the finite-element analysis. A one-gear blank case study is used to demonstrate the optimization scheme.     

萃取预分离法分离富铕中钇矿新工艺

采用一种新的串级萃取方式--萃取预分离法分离富铕中钇矿的新工艺.原料首先流入十几的三出口预先粗分离工艺,其萃余液La～Gd(TbDy)直接流入Nd/Sm工艺;中间出口流入(Gd)Tb～HoY(Er)Gd～Dy/Ho～LuY细分离工艺;出口负载有机相(Ho)Er～LuY流入Gd～Dy/Ho～LuY的洗涤段.结果表明,新工艺的粗分离工艺将占原料约70%的La～Gd(TbDy)预分离掉,使流入Gd～Dy/Ho～LuY工艺的稀土量减少约70%;由于Gd～Dy/Ho～LuY分组的萃余液GdTbDy含Ho2O3小于0.03%,省去原工艺的GdTbDy/HoY分离;新工艺的处理能力提高30%,酸碱消耗减少20%以上,贵重稀土元素Eu和Tb的存槽量大大减少.     

AlF3贮仓料位计在线监控系统开发与应用

针对铝电解原材料中AlF3与Al2O3自动配料不准和难于观察及控制的现象，我厂开发应用了AlF3贮仓料位计，并与微机网络相连，实现了远程测量与在线监控，使AlF3配料更准确更均匀，电解质分子比更稳定，电解槽生产低耗高效。     

回火过程应力场计算机模拟

回火过程应力场计算机模拟林家骝，杨振枢，于震宗，段贵明（清华大学）郭剑仁，史全兴，谢克仁（内蒙古第一机器厂）ＡＳｔｕｄｙｏｆＮｕｍｅｒｉｃａｌＳｉｍｕｌａｔｉｏｎｏｆＳｔｒｅｓｓＦｉｅｌｄｄｕｒｉｎｇＴｅｍｐｅｒｉｎｇ￥ＬｉｎＪｉａｌｉｕ；ＹａｎｇＺ...     

溶液法制备高接枝率HDPE-g-MAH

用溶液法制备了HDPE -g -MAH,并讨论了单体、引发剂用量、反应温度、反应时间、投料方式等因素对产物接枝率的影响。     

水性聚氨酯材料配方设计技巧

介绍了优选法的0.618法和分数法,对其进行改进创新和原理证明,并应用于生产涂料配方设计中。     

粉末涂料涂装工艺(Ⅰ)

介绍了粉末涂料的几种涂装方法及其原理、特点、应用范围和进展情况，重点介绍了静电粉末涂装方法。     

容器焊缝错边残余应力与载荷应力的测定研究

本文对焊接容器错边和不错边的焊接接头进行了电测法的残余应力测试，确定了焊接残余应力的大小及方向，并在加载的条件下，对各焊接接头测点进行了综合应力测试，并给出了受载条件下的应力分布。     

熔体塔式造粒法生产尿基复混肥

化肥企业生产尿基复混肥对于农业科学施肥、提高肥料利用率、避免环境污染及促进企业产品结构调整都具有十分重要的意义。熔体塔式造粒法生产尿基复混肥较之其它方法优越性更为显著,笔者简要介绍该法的生产机理、工艺流程、技术特点、国内现状及产品市场前景等方面的一些情况。