浓硫酸中904L不锈钢焊接接头的耐蚀性能

采用动电位极化曲线和电化学阻抗谱研究了904L不锈钢基体和焊接区在浓硫酸溶液中的腐蚀行为,并简要分析其腐蚀机理.实验结果表明：焊接区和基材的阴极极化曲线均为氢还原反应过程,而阳极极化曲线则有较大的差异.焊接区相对于基材,其自腐蚀电位降低且阳极电流增大,焊接对阳极反应起促进作用.904L不锈钢基体和焊接区的腐蚀主要由电化学反应步骤控制,两者的Nyquist图特征相似,均由单一的容抗弧构成,有一个时间常数.基体的耐蚀性能优于焊接区.     

2507双相不锈钢在湿法炼锌中的应用

采用冲刷腐蚀法研究了浆料离子组成、p H值和温度对2507型双相不锈钢和904L奥氏体不锈钢耐腐蚀性能及电化学性能的影响,并对二者的力学性能进行了对比,结果表明2507型不锈钢对料浆中Cl-和F-、料浆p H值、温度的耐腐性明显优于904L型不锈钢,且前者力学性能优异,可以应用于湿法炼锌的搅拌器设备当中。     

氮离子注入关节假体材料的耐蚀和耐磨性能

本文采用阳极极化技术相关节假体材料摩擦磨损筛选机,在相同的试验条件下比较了目前使用的关节假体材料,UHMWPE,CoCrMo合金,Ti6A14V合金和316L不锈钢的耐蚀和耐磨性能。研究了氮离子注入三种金属材料对其耐蚀和耐磨性能的影响,分析了氮离子注入后的表面成分分布。试验结果表明,Ti6A14V合金的耐蚀性能优于CoCrMo合金和316L不锈钢,Ti6A14V合金和CoCrMo合金的耐磨性能相当。氮离子注入三种金属材料后提高其耐蚀和耐磨性能,UHMWPE对磨末注入氮离子和注入氮离子金属的磨损率小于0.55μm/a,与体内关节假体平均磨损率0.15mm/a相比,可以认为是“零”磨损。     

螺旋板式换热器在湿法炼锌厂的应用

分析了螺旋板式换热器在使用中的特点,发现螺旋板式换热器具有换热效率高、设备耗费少等优点。介绍了螺旋板式换热器在湿法炼锌厂生产使用中发现的问题和相应解决方法。生产实践表明,选择904L不锈钢作为换热板材的材质,在高温废酸环境下具有较长的使用寿命,并提出采用耐腐蚀性能更好的石墨代替904L的构想。     

铝阳极氧化膜的低温封孔

本文介绍一种含1．45g/L镍离子、0．5g/L氟离子及表面活性剂的溶液的低温封孔方法。根据试验结果分析了温度、pH值及处理时间对这种低温封孔质量的影响。用这种封孔所得到的氧化膜与传统的沸水封孔相比，具有更好的耐蚀、耐污染性及更加光泽的表面。     

不锈钢酸洗废水中有价组分梯级分离及酸再生研究

不锈钢酸洗废水通常采用石灰中和,产出大量危险固体废弃物(硫酸钙渣)。对不锈钢酸洗废水有价组分梯级分离及硫酸再生硝酸/耦合制备硫酸钙晶须展开研究。考察了高酸环境氟离子脱除、有价金属梯级分离及酸再生三个工序不同因素对试验结果的影响。借助SEM对酸再生过程耦合产出的硫酸钙晶须形貌进行分析,确定了各工序的最佳工艺条件。结果表明,氟离子在高酸环境下脱除率97%;铁、镍和铬的选择性沉淀率均99.9%;硝酸高效再生并耦合产出硫酸钙晶须,硝酸再生率95%,再生硝酸浓度超过143g/L。为不锈钢酸洗废水处理提供了一种可靠的新技术,且工艺稳定。     

不锈钢粉末与丝网烧结多孔材料高温硫化性能研究

为了考察滤材结构和形貌对材料抗高温硫化性能影响,研究了不锈钢316L、310S粉末与丝网烧结多孔材料在高温硫化氢气氛[350℃,介质:CO2+H2S(0.02％,体积分数)]中的硫化性能以及材料孔结构的稳定性,并利用光学显微镜观察表面形貌,从而评价耐蚀性能.结果表明:经过1 500h试验,316L、310S粉末烧结金属多孔材料在高温硫化氢气氛中耐腐蚀性能明显低于同类丝网材料,粉末与丝网烧结金属多孔材料的耐蚀性能差异主要由滤材结构和其比表面积决定.     

446超纯铁素体不锈钢耐蚀行为研究

采用电化学测试、化学浸泡等方法对比研究了超纯铁素体不锈钢446与TA2钛材及超级奥氏体不锈钢904L耐蚀性。结果表明,超纯铁素体不锈钢446在含Cl^-环境中具有较好的耐蚀性,在一定条件下,可替代TA2钛材应用在一些含氯化物介质中;在还原性的盐酸和硫酸介质中,超纯铁素体不锈钢446表现出良好的耐腐蚀性能,耐蚀性优于904L不锈钢。     

利用吸氮方法处理的无镍不锈钢制品制造工艺的开发

1前言 以SUS316L钢为代表的奥氏体不锈钢具有高力学强度和优良的耐蚀性能，在工业材料、民用品、生物材料中得到了广泛的应用。但是，现有奥氏体不锈钢依然容易发生缝隙腐蚀和孔蚀，希望能进一步改善其耐蚀性。另外，奥氏体不锈钢大多数添加有高浓度的镍，镍有可能引起金属过敏。而且，作为生物植入材料使用时，镍的过敏等长期毒性也引起人们的注意。为了解决这些问题，以1％左右的氮代替镍改善力学强度和耐蚀性的无镍不锈钢，作为生物用金属材料受到关注。     

超纯铁素体不锈钢脆性及形成特点对性能的影响

超纯铁素体不锈钢是一种具有良好耐蚀性能、加工性能和焊接性能的材料,主要应用于汽车行业、厨房用具和家用电器以及大型建筑的屋面设计等领域.主要研究超纯铁素体不锈钢脆性形成原因以及对性能的影响,总结了超纯铁素体不锈钢σ相脆性、475℃脆性和高温脆性等主要特征,并对其脆性形成的原因进行了详细分析,认为σ相,x相,α相,Lave...     

Comparative Evaluation of Low Nickel and Nickel Free Lean Duplex Stainless Steels with 316L in a Variety of Corrosive Media

For many applications duplex stainless steels with their superior strength coupled with lower raw material cost have emerged as an attractive alternative to austenitic stainless steels. With emphasis on conservation of scarce resources like nickel and molybdenum there is continuing endeavour to develop essentially molybdenum free lean duplex stainless steels with low nickel content such as 2304 (23Cr–4Ni), 2202 (22Cr–2Ni), 2101 (21Cr–1.5Ni). This paper compares the corrosion behaviour of a low nickel duplex (21Cr–1.5Ni) and a nickel free duplex (21Cr–1.5Cu) with 316L stainless steel in several corrosive media. All the three alloys exhibit similar excellent corrosion resistance under boiling conditions in less aggressive organic acids such as 20 % acetic acid, 25 % lactic acid, 25 % citric acid. However, in stronger organic acids such as 5 % formic acid, 5 % oxalic acid, and mixture of formic and acetic acid, the duplex grades exhibit superior corrosion resistance. This edge over 316L continues on addition of chloride ions in these acids. In boiling 50 % nitric acid solution, the corrosion resistance of these nickel free and low nickel duplex is slightly better than 316L grade. Since 304L grade is generally used in nitric acid plants, tests were also conducted on 304L and these duplex grades were found to be more resistant. Similarly in 50 % phosphoric acid also, the duplex grades exhibit superior corrosion resistance compared to 316L grade. Alloying with nickel and molybdenum is known to give rise to significant improvement in corrosion resistance in this acid. However, even in the absence of these elements, the beneficial effect of higher chromium content is evident. Of all the inorganic acids, sulfuric acid is used in largest volume in the industries. Boiling tests in dilute 1 and 5 % H₂SO₄ indicate that nickel free copper bearing duplex is more resistant than low nickel duplex grade and vastly superior to 316L Thus nickel-free and low-nickel duplex stainless steels offer a very attractive combination of high corrosion resistance coupled with cost effectiveness in a wide variety of corrosive media.     

硅对含强氧化性离子沸腾硝酸中奥氏体不锈钢耐蚀性的影响

 超低碳Cr Ni奥氏体不锈钢在含强氧化性离子的硝酸溶液中会发生过钝化腐蚀和晶间腐蚀,而高硅不锈钢在强氧化性浓硝酸中具有优良的耐蚀性。笔者以高纯级000Cr25Ni20和00Cr14Ni14Si4钢作为对比材料,发现在纯稀硝酸中000Cr25Ni20钢具有更优良的耐蚀性,在不同含量的40%沸腾硝酸溶液中,00Cr14Ni14Si4钢可有效抑制过钝化腐蚀,而且不发生晶间腐蚀。     

Cr-Mn-N奥氏体不锈钢的晶间腐蚀性能研究

晶间腐蚀性能是钻铤结构件用奥氏体无磁不锈钢的重要性能之一.采用不锈钢10％草酸浸蚀试验方法、不锈钢65％硝酸腐蚀试验方法以及不锈钢硫酸-硫酸铜试验方法对三种不同成分的Cr - Mn -N奥氏体不锈钢做了晶间腐蚀试验.试验结果表明,A钢种在不同的腐蚀条件下均具有良好的耐晶间腐蚀性能,该材料按0.03％C、18.96％ Cr、0.57％N的化学成分设计可以达到优良的耐晶间腐蚀性能.     

Recent developments in stainless steels:austenitic,ferritic,duplex

A review is given concerning some of the recent industrial developments of stainless steels. In austenitic stainless steels,two different directions of alloy development are noticeable:low nickel austenitic stainless steels and high nitrogen stainless steels.In these two cases the aims are different,particularly in terms of strength,but the philosophy of alloy development and the scientific approaches are very similar and they all revolve about the role of nitrogen as an alloying element and how this affects strength,ductility and corrosion resistance. There is now a broad and useful basis of information as to how nitrogen affects solid solution hardening,grain boundary hardening and work hardening and how to make use of these effects in developing materials required by the world market. In the field of corrosion resistance,ferritic,duplex and austenitic stainless steels compete with each other and now there is a growing body of information concerning the relative corrosion resistance based on laboratory data. However,for practical applications and for alloy selection,more than just laboratory data are needed,and thus,the first results are presented here of a many years comparison of the corrosion resistance of 24 commercial stainless steels exposed to corrosion in outdoors marine atmosphere.Hope is expressed to involve in the near future even more steels from a wider range of manufacturers in such corrosion studies.This might help consumers in appropriate alloy selection.It might also help steel makers in developing appropriate stainless steel grades.     

超级高氮奥氏体不锈钢的耐腐蚀性能及氮的影响

用电化学测试、化学浸泡等方法研究了超级奥氏体不锈钢00Cr24Ni22Mo7Mn3CuN(654SMO)的耐点腐蚀和耐缝隙腐蚀的性能。通过改变氮含量,研究了氮对奥氏体不锈钢的耐点腐蚀和耐缝隙腐蚀性能的影响,结果表明,氮和适量的铬、钼结合,能显提高奥氏体不锈钢的耐点腐蚀和缝隙腐蚀的能力,并且随着氮含量的增国,砥体不锈钢的耐点腐蚀和耐缝隙腐蚀的能力也增强,对比实验表明,超级奥氏体不锈钢在耐点腐蚀,缝隙腐蚀等局部腐蚀性能方面可以和镍基合金C－276媲美,甚至优于镍基合金。     

Effects of nitrogen oxides,sulfur dioxide,and ferric ions on the corrosion of mild steel in concentrated sulfuric acid

Effects of nitrate ions, nitrous acid, sulfur dioxide, and ferric ions on the corrosion of mild steel in unstirred, concentrated sulfuric acid were determined in laboratory tests. Nitrate and nitrous acid at levels up to 1000 ppm accelerate corrosion. At concentrations greater than 1000 ppm nitrate passivates the steel. Sulfur dioxide and ferric ions have no detectable influence on the corrosion. Reaction mechanisms are presented to explain the observed effects. The impact of nitrogen oxides on the storage and handling of sulfide smelter by-product acid is discussed.     

低镍不锈钢生产中的若干冶金学问题

高氮低镍不锈钢具有良好的强度、延展性及耐腐蚀性能，且可以降低晶界的腐蚀敏感性。同时，以低成本的氮代替昂贵的镍可以降低生产成本。简要回顾了我国及世界不锈钢产业的发展历程，分析了低镍不锈钢中氮的作用及不锈钢中加氮工艺等一系列问题，并对不锈钢生产中存在的若干冶金学问题进行了总结。     

新型汽车排气系统用铁素体不锈钢的冷凝液腐蚀研究

 铁素体不锈钢中Cr元素对其耐腐蚀性能起着非常重要的作用。本文采用实验室冷凝液腐蚀实验方法,对一系列汽车排气系统用铁素体不锈钢在实验室模拟冷凝液中的腐蚀性能进行了研究。所有钢种经过10周期的实验室冷凝液腐蚀实验后,研究结果表明：Cr当量高于17%的铁素体不锈钢与含17%Cr的铁素体不锈钢耐实验室冷凝液腐蚀性能相当,且平均腐蚀失重量均小于6g/m2,平均最大腐蚀深度均小于0.03mm。在此实验结果的基础上,对新开发的439M型铁素体不锈钢和409L型铁素体不锈钢进一步开展5周期、10周期、20周期的实验室冷凝液腐蚀实验,并使用极值分析方法对三种周期冷凝液腐蚀实验后样品的最大点蚀深度进行统计分析,研究结果表明,新开发的439M型铁素体不锈钢的预测寿命是409L的1.6倍。     

Nickel Release Rate of Several Nickel-containing Stainless Steels for Jewelries

Nickel-containing stainless steels have been widely applied in watch and jewelry production,and their responses to the Nickel Directive become a universal concern in the industry.The nickel release rates and corrosion behaviors of types 316 L,304,303 and 201stainless steels under the conditions of solid solution and mirror polishing were studied by artificial sweat soaking and electrochemical methods.The results show that the weekly nickel release rates in artificial sweat do not strictly correspond to the nickel contents,which present a descending order as 303 stainless steel of 2.06μg/cm2,201 stainless steel of 1.51μg/cm2,304 stainless steel of 0.08μg/cm2 and 316 L stainless steel of 0.02μg/cm2.Both the nickel release rates of type 303 and 201stainless steels significantly exceed the threshold values regulated in EN1811∶2011;therefore,they should be avoided to be used as watch and jewelry materials owing to the risk of nickel sensitization.The nickel release rates of 316 Land 304stainless steels meet the requirements of the standard.Sulfide inclusions in stainless steel become the sources of pitting and exacerbate the damage of the passivation membrane,which is the significant cause to enhance the nickel release rates.     

Mechanical properties improvement of PM 400 series stainless steels via nickel addition

PM 409L and 434L grades of stainless steels have recently been selected at the optimum materials for automotive exhaust system applications, such as flanges and HEGO bosses. These applications are much more demanding than the most current PM stainless steel applications in terms of mechanical properties, weldability, and resistance to corrosion and thermal fatigue. Also important for these applications are elevated temperature mechanical strength, impact strength and resistance to stress relaxation at elevated temperatures. Significant improvements in both the room and elevated temperature mechanical stregths of these PM materials can be achieved by alloying with small amounts of nickel. The benefits of this approach are found to be significant in the case of 409L and moderate in the case of 434L.