Effect of Precipitation on Intergranular Corrosion Resistance of 430 Ferritic Stainless Steel

With Nb-Ti-stabilized 430 ferritic stainless steel(NTS430FSS) and SUS 430 ferritic stainless steel(SUS430FSS) as experimental materials, the influence of precipitation on intergranular corrosion resistance was investigated. A series of aging treatment were carried out. The free-exposure corrosion test and double loop electrochemical potentiokinetic reactivation(DL-EPR) test with a scan rate of 1.67 m V/s at 26 °C were applied to evaluate the intergranular corrosion(IGC) resistance. Metallographic observation, scanning electron microscope(SEM), transmission electron microscope(TEM) with energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD) analysis were conducted. The results show that IGC occurred in SUS430 FSS aged above 700 °C, while it occurred in NTS430 FSS as the temperature was improved to 1 050 °C. The critical degree of sensitization Ir/Ia reaches 0.305 in SUS430 FSS, which is higher than that of NTS430 FSS, i.e. 0.010, aged at 950 °C for 2 h. The TEM, EDS and XRD results show that a large amount of Cr23C6 precipitates with size of 60 nm×22 nm are located at the SUS430 FSS grain boundaries as chains. With the addition of Nb and Ti and reduction of C, the amount of precipitates reduces significantly in NTS430 FSS. A majority of Cr23C6 were replaced by Ti C and Nb C. Only a small amount of spherical Ti C(R=186 nm) and square Ti N(312 nm×192 nm) with Nb and Cr adsorbed are left along grain boundaries. Due to the dual stabilization of Nb and Ti, the precipitation of Cr23C6 is restrained, the chromium depleted region is avoided and accordingly the resistance to the intergranular corrosion is improved.     

分别使用奥氏体、铁素体和双相不锈钢焊条时AISI409M铁素体不锈钢焊缝的疲劳裂纹扩展行为

铁素体不锈钢（FSS）可在不太苛刻的腐蚀环境中使用，如化工设备、各种炉子部件、热交换器、油燃烧器部件、石油精炼设备、保护套管、回收装置、存储容器、电器、太阳能热水器和家用器具等。由于FSS焊接过程没有相转变，不能够产生晶粒细化的作用，因此在焊缝和热影响区晶粒粗大，从而带来韧性和塑性差的问题。当然，     

合金钢中铜的快速测定（PAN—CPB）光度法

本文主要应用溴代十六烷基吡啶（CPB）作为增溶济,用氨三忆酸掩蔽铁、镍、钨、钼、钒等金属离子,以1－（2－吡啶偶氮）－2－萘粉（即PAN）为显色剂,不必采用分离、过滤或萃取等手续,可直接测定合金钢中铜。方法简便、快速、准确。且络合物稳定性良好。0－50％μgCu/34ml,符合比尔定律。测定范围0．01－0．50％Cu     

第八届国际铁合金大会筹备工作简讯(续三)

液态高碳锰铁的热力学[JoFenstad，Jo－hanKr．Tuset（挪威科技大学，挪威）］对液态高Mn的Fe－Mn－C系统在1300—1650℃、压力为0．01—1大气压下建立了下列平衡：MnO（固）＋C=[Mn]十CO（气）根据所得的结果和从文献中查得的数据，得出了整个体系的C、Mn、Fe活度。硅铁炉的操     

电磁搅拌电源逆变器故障分析

某钢厂连铸机末端电磁搅拌电源故障,对其进行修复后分析电源故障原因。电源的驱动部分是以CONCEPT公司的IGD515技术为核心设计,逆变主回路的IGBT模块选用丹尼克斯的DIM1600FSS12-A000。通过对现有的外围电路参数的推算,计算出IGBT过流保护阈值和驱动信号封锁时间,验证设计是否合理。     

高炉鼓风机防喘控制系统的应用

在对传统的防喘控制系统研究的基础上,引进了微机作为控制系统的核心,开发出新一代的防喘控制系统ASC－01,最大限度的克服了常规系统的局限性,实现了喘振线的实时跟踪及放空线的实时修正补偿。达到最小放空量的要求,并提高了控制水平。     

变形对汽车用铁素体不锈钢微观组织及抗氢性能的影响

铁素体不锈钢(FSS)具有良好的成形性能、低成本和耐腐蚀性能,被广泛应用于汽车制造等行业.本文通过对退火态、轧制20％、轧制40％的AISI430铁素体不锈钢进行4h的电化学充氢,研究了变形对汽车用AISI430铁素体不锈钢组织性能的影响和氢脆断裂机理.轧制态铁素体不锈钢具有较高的氢脆敏感性,氢对材料力学性能影响显著,...     

借鉴发达国家经验 推进我国行业协会发展——北欧三国行业管理考察报告

借鉴发达国家经验推进我国行业协会发展 ——北欧三国行业管理考察报告 执笔：高凯　 文章编号：文章编号：1009－0622(2001)01－0014－03 　　为了配合政府机构改革、转变职能、加强行业管理，按照建立社会主义市场经济体制的要求，借鉴国外市场经济发达国家的成功经验，进一步推进我国工业行业协会的法制化、规范化建设，经国家经贸委批准，中国工业经济联合会组团于2000年8月11～24日赴瑞典、挪威和丹麦三国就其有关工业管理体制和工业行业协会的地位和作用等问题进行了专项考察，中国钨业协会副会长兼秘书长孔昭庆随团参加了考察。 作者单位：执笔：高凯（中国工经联行业管理考察团）     

Low molybdenum ultra-pure ferritic stainless steel for solar water heaters

In order to meet the demands of service life and the synthetical performance/price ratio of stainless steel in the solar water heater industry,the low molybdenum ultra-pure ferritic stainless steel(FSS) B445J1M was developed at Baosteel.In this study,comparative studies were carried out on the mechanical properties,the formability and the corrosion resistance of B445J1M,304 and 444,and the advantages and application fields of B445J1M were summarized.     

Development of ferritic stainless steel B445R with superior corrosion resistance for architectural applications

The dull-finish ferritic stainless steel(FSS) sheet B445R for architectural roofing has been developed by Baosteel.This steel product exhibits excellent corrosion resistance superior to that of SUS 316L with a lower cost.It can be easily formed into roofing panels by ordinary processes.Moreover,the thermal strain of it is less than SUS 316L because of its lower thermal expansion coefficient,and its reflectivity is lower due to the dull-finish treatment.All of these features make it capable of being used as architectural roofing materials in coastal regions.     

不锈钢热轧层流冷却过程的温度模拟

通过对不锈钢热轧层流冷却过程的传热特性分析,建立了不锈钢热过程数学模型,并对层流冷却过程的典型工况进行了数值模拟,得出了不锈钢层流冷却过程中温度的变化规律,为不锈钢层流冷却过程的优化控制提供了依据。     

200系列不锈钢中多元素的X-射线荧光光谱分析

采用全自动制样,应用波长扫描X-射线荧光光谱分析法对200系列不锈钢中Si、Mn、P、S、Ni、Cr、Cu、Mo、V、Ti、Nb、Co、W等多元素进行测定。选择非相似多元不锈钢标准物质,主要采用基本参数法,结合PH模式的经验系数法校正光谱干扰和基体效应,同时加入了光谱波长、能量重叠校正和高次荧光校正来消除光谱干扰和严重的基体效应。通过精密度测试和对比试验表明,该方法用于在线分析200系列不锈钢中多个元素,工作曲线延展性好,精密度高,检测值与标样认定值比对结果理想,贵重金属Ni、Cr、Mn测量精密度0.003%-0.015%,准确度高、快速,重复性好,具有良好的稳定性。     

不锈钢厂电弧炉烟尘处理技术

不锈钢厂电弧炉烟尘主要由炉内高温区合金元素和组分的挥发、脱碳反应生成的CO气泡破裂所形成的金属和炉渣液滴的飞溅、被尾气直接带走的小颗粒炉料组成。与普碳钢或低合金钢厂电弧炉烟尘比较,不锈钢电弧炉烟尘含有更多的合金元素,但锌含量较低。目前不锈钢厂所采用的回收处理烟尘的工艺以熔融还原工艺为主。     

包钢某工程电气室防磁区不锈钢钢筋施工工艺

文章主要介绍了某工程中的电气室防磁区采用不锈钢钢筋施工工艺,从不锈钢筋的特点入手,对不锈钢筋施工工艺流程进行了介绍,重点对不锈钢筋的绝缘及绑扎施工技术进行了总结,并对此种新材料的实际应用经验进行必要的总结。     

304不锈钢精密钢带表面“炉灰”缺陷分析

 在304不锈钢精密带光亮退火生产环节，钢带表面易出现金属粉的现象，导致产品表面质量存在不稳定性。针对304不锈钢精密钢带表面出现的“炉灰”缺陷，利用扫描电子显微镜观察其形貌，并用能谱仪对缺陷处局部成分进行了点扫描和面扫描检测。结果表明，304精密钢带“炉灰”缺陷微观形貌为白色微颗粒。结合能谱微区分析结果和相关研究分析，推测“炉灰”缺陷主要是由于304不锈钢基体组织中硼元素质量分数过高，钢带在光亮退火过程中硼原子易与保护气氛中分解的活性较高的氮原子结合，生成氮化硼析出而形成的。通过控制不锈钢基体中硼元素质量分数不大于0.001 5%，从而达到有效降低304不锈钢精密钢带“炉灰”缺陷的目的。     

Influence of Protective Coating at High Temperature on Surface Quality of Stainless Steel简

A ceramic matrix coating for minimizing steel loss of stainless steel at high temperatures was prepared by handled air-spraying technique, and the influence of coating on surface quality of stainless steel was mainly investiga ted in laboratory. Experimental results showed that the protective coating reduced the oxidation of stainless steel by more than 91% and minimized high temperature scaling and also enhanced steel surface quality. The scales of coated specimen were removed completely and the scales of uncoated specimen were partly residual on the surface after cool ing process. Mn-rich and Fe-rich zones were found in the oxides. The Cr2 O3 found in scales came from the underlying stainless steel and formed a Cr rich layer along the spalled surface.     

地下连续墙在深基坑工程施工中的应用

介绍了地下连续墙工法在宝钢不锈钢热轧漩流池深基坑施工的工艺和技术,与常规施工工法相比,技术先进合理,工作效率高,应用效果良好.     

S32760超级双相不锈钢冶炼连铸工艺研究

介绍了太钢S32760超级双相不锈钢氮气合金化工艺以及钢质纯净度控制技术。通过建立合理的AOD炉氮气合金化控制模型,可以实现对成品N含量的精确控制;通过采取Al、Si-Ca复合脱硫脱氧工艺,可以提高钢质的纯净度水平,为后续的热加工创造较好的条件。     

热轧SUS304不锈钢带工艺研究及质量分析

1780 mm热连轧机设备水平先进,适合生产热轧不锈带钢.在研究生产工艺的过程中,结合不锈钢生产特点,研究制定了SUS304热轧不锈带钢的生产工艺,并对不锈带钢轧制结果进行了分析,结果表明不锈带钢的生产工艺稳定、合理.     

不锈钢-碳钢复合带肋钢筋的制备工艺研究

使用金属熔覆和热轧的方法成功制备了覆层为Cr13不锈钢的复合钢筋.通过有限元数值模拟发现,在粗轧区域的高温变形过程,塑性应变主要集中在轧件表层和1/4位置,芯部的变形较表层偏小,随着变形的不断进行,塑性应变不断向碳钢芯部渗透.复合钢筋在成品机架K1变形时,不锈钢全部包裹在碳钢上,但是在横断面的不锈钢覆层厚度分布不均匀,...