圆锯片的有限元模态分析

针对金属冷热锯机锯片在锯切轧件过程中出现的振动问题 ,利用 MSC/ NASTRAN有限元软件 ,计算分析了各种参数对锯片模态的影响。从而为锯片的设计及其制造工艺的确定提供了可靠的参考依据 ,为最终解决生产中的实际问题发挥了重要作用     

含Cl^-溶液中SO4^2-对316不锈钢临界点蚀温度的影响

采用外加恒电位下腐蚀电流-温度扫描方法研究了在0．5％Cl^-溶液中，SO4^2-浓度对316不锈钢点腐蚀行为的影响．结果表明，随着SO4^2-浓度的增加，钝化电流增加，开路电位降低．当SO4^2-浓度低于0．42％时，316不锈钢的临界点蚀温度比不存在SO4^2-时的临界点蚀温度低；当SO4^2-浓度大于0．42％时，临界点蚀温度比不存在SO4^2-时的临界点蚀温度高．从离子竞争吸附的角度进行分析，对SO4^2-加速与抑制点蚀两种作用规律的形成原因进行了解释．     

不锈钢GTAW焊焊接中的氧化试验研究

对于不锈钢的焊接，在NDT检测中仅对夹渣、未熔合、未焊透、气孔等缺陷均有评定标准，而对菜花状缺陷、树瘤状氧化缺陷、蓝脆现象、氧化现象等却没有评定方法及标准。为此，以不锈钢管的焊接试验为主鲒合不锈钢板的焊接，针对不锈钢在GTAW焊焊接中氧化缺陷的防止方法、氧化评定及检测标准提出几点看法，供行业界借鉴与批评指证。     

(Short communication) Degradation of corrosion resistance of Zircaloy-4 in LiOH aqueous solution

To investigate the degradation of corrosion resistance of Zircaloy-4 in LiOH aqueous solution, SIMS (secondary ion mass spectrometry) analysis was performed to examine the profiles of Li~ , K~ , and OH~- in oxide layers formed in the same concentration (0.1 mol/L) LiOH and KOH solutions. Even though the oxide layers have an equal thickness, the penetration depth of K~ is shallower than that of Li~ , and the penetration depth of OH~- corroded in KOH solution is also shallower than that corroded in LiOH solution. It shows that the diffusion of OH~- into oxide layer is accompanied by the corresponding cation. The difference of degradation effect of LiOH and KOH solutions on the corrosion resistance of Zircaloy-4 was discussed.     

Influence of electroplating conditions on magnetic properties of Fe-36wt.% Ni alloy film

A Fe-Ni soft magnetic film was prepared in sulphate solution by electroplating. The influences of the molar ratio of n [Fe2+ ]/ n [Ni2+ ], current density, bath temperature, pH and L-ascorbic acid concentration on magnetic properties of Fe-Ni alloy film were investigated. The results show that the saturated flux density(BS) of the film increases initially and decreases after it reaches the specific value with the increase of n [Fe2+ ]/ n [Ni2+ ] molar ratio, current density, bath temperature and pH. However, the relationship between L-ascorbic acid concentration and B S keeps linear. It is observed that the coercive force( Hc) is enhanced with the increase of n [Fe2+ ]/ n [Ni2+ ] molar ratio, current density and pH. By comparison, when the bath temperature increases, Hc always decreases. With the increase of L-ascorbic acid concentration, the coercive force increases initially and then decreases.     

Abnormal Austenite-Ferrite Transformation Behaviors of Fe-ISi: Dilatometric Measurements

WITH THE APPEASING of competition of the totaloutput of iron and steels, the new generation of ultrahigh strength steel, based on the lessen the burden ofenvironment, double improvement of mechanicalproperties and elongation of the serving life, has beenfully outspreaded in the world. More and more researchwork shows that the solid-state microstructureevolution becomes the most effective route in thedevelopment of ultra-high strength steels. A process ofgreat interest in the steel produc…     

INVESTIGATION ON CRYSTALLIZATION KINETICS OF Pd-Cu-Si GLASS

The crystallization kinetics of Pd-Cu-Si glass was studied by means of diferential scanningcalorimetry-Ⅱ.According to Kissinger peak shift meth(?)d and Arrhenius equation,theapparent activation energy was calculated.The crystallization kinetics follows Johnson-Mehl-Avrami equation with n=3.0 within 0.15相似文献   

制镁还原罐的研制

从含镁的矿石中提炼金属镁的方法已不仅仅是电解法 ,还有目前广泛采用的真空还原法 (皮江法 ) ,但其所用的还原罐寿命短、价格高一直是困扰着国内、国外生产的难题。用研制出新的材料和改革后的铸造工艺生产出的还原罐 ,较好地解决了上述问题 ;并达到国内、国外先进水平。     

离心铸造大口径球铁管用复合功能型脱硫剂的研制

为使硫量波动的高炉铁液能适应大型离心铸造球铁铸管生产,研制了一种成本较低廉、添加操作简单的复合功能型脱硫剂。其主要组分包括强脱[S]去[O]材料钝化镁粒、碳化钙,增加石墨核心元素Zn和膨胀集渣材料珍珠岩,以及能抑制反球化作用和净化铁液的材料等。采用冲入法进行球化处理,这种脱硫剂覆盖在球化剂和孕育剂上,使用方法简单,效果良好。