Corrosion of two kinds of cast steels containing chromium in hot concentrated alkaline

A typical hot concentrated alkaline corrosion environment exists in alumina metallurgical industry, so that steel materials with outstanding alkaline corrosion resistance are strongly demanded for its processing equipment. In this paper, the corrosion resistance of two kinds of martensitic cast steels containing chromium in static 303g/L NaOH alkaline solution at 85℃ was studied through polarization and potential-time curves, corrosion weight loss and corrosion morphology analysis. Experimental results showed that protection effect by passive film of cast steel containing Cr was temporary. The low carbon steel without Cr content also exhibited chemical passivity in the same solution. The corrosion mode of the tested Cr-containing cast steel was composed of active dissolving corrosion and caustic embrittlement cracking. Dissolving corrosion was the primary mechanism for the induced weight loss, while severe caustic embrittlement cracking was secondary. With the increase of chromium content in the cast steel, the tendency of the caustic embrittlement cracking decreased, while the active dissolving corrosion increased.     

Microstructure refinement of Sn-Sb Peritectic alloy by power ultrasonic

Sn-Sb peritectic alloy was treated with 400 W, 600 W and 800 W ultrasonic, respectively, to study the effect of power ultrasonic on solidification microstructure. Results show that power ultrasonic can refine α phase and β phase of the alloy, as well as eliminate gravitational segregation. Moreover, 600 W ultrasonic demonstrated the best refining effect, not only homogenous and fine solidification microstructure can be obtained, the cubical β phase crystals can also be spheroidized.     

INFLUENCES OF TRACE ADDITIONS OF STRONTIUM AND PHOSPHORUS ON ELECTRICAL RESISTIVITY AND VISCOSITY OF LIQUID Al-Si ALLOYS

ＩＮＦＬＵＥＮＣＥＳＯＦＴＲＡＣＥＡＤＤＩＴＩＯＮＳＯＦＳＴＲＯＮＴＩＵＭＡＮＤＰＨＯＳＰＨＯＲＵＳＯＮＥＬＥＣＴＲＩＣＡＬＲＥＳＩＳＴＩＶＩＴＹＡＮＤＶＩＳＣＯＳＩＴＹＯＦＬＩＱＵＩＤＡｌＳｉＡＬＬＯＹＳ①ＧｕｉＭａｎｃｈａｎｇ，ＪｉａＪｕｎ，...     

原子吸收分光光度法测定土壤中的镍的方法研究

本文对微波消解-原子吸收分光光度法测定土壤样品中的镍元素的分析方法进行了探讨,并对不同类型土壤消解后赶酸与不赶酸的测定结果进行了比较。结果表明,原子吸收法测定土壤中的镍必须赶酸,但赶酸的方法可以简化,并利用连续光源原子吸收光谱图进行了验证。     

Reaction of (C_5H_5)_2NdCl·2LiCl with n-Butyllithium: Formation and Crystal Structure of [Li(DME)_3][(C_5H_5)_3Nd(μ-H)Nd(C_5H_5)_3]

Reaction of (C_5H_5)_2NdCl·2LiCl with n-Butyllithium: Formation and Crystal Structure of [Li(DME)_3][(C_5H_5)_3Nd(μ-H)Nd(C_5H_5)_3]     

固体超强酸催化合成乙酸松油酯的实验与应用

使用自制的固体超强酸催化剂 ,将松油醇和乙酸酐合成乙酸松油酯 ,催化剂用量 3% ,反应时间 3h,反应温度 40℃ ,松油醇转化率 99% ,乙酸松油酯选择性 97% ,分馏得到纯度 95 %的产品 ,生产工艺进入中试阶段。     

地钱素R的合成及表征

以2-羟基-3-甲氧基苯甲醛、5-溴-2-甲氧基苯甲醛、4-溴苯甲酸甲酯和3-羟基-4-甲氧基苯甲醛为原料,通过Ullmann、醛基还原、磷盐生成、Wittig、分子内的Wittig、酚羟基与醛基的保护和脱保护以及烯烃的催化氢化反应等方法完成了标题化合物的全合成。所得化合物的结构经MS、1HNMR进行确证。     

腺嘌呤磷酸盐锁核酸的合成

以双丙酮-D-葡萄糖为起始原料,通过氧化,还原,亲核取代,水解等19步反应合成标题化合物,总产率8.5%,其结构通过1HNMR和MS表征。