低氢气氛在不锈钢带光亮退火中的应用

所指低Ｈ２，是２５％Ｈ２和７５％Ｎ２的混合气，由氨分解气和工业Ｎ２以１：２混合后经净化制得。用以替代氨分解气，作不锈带钢连 续光亮退火的保护气氛。在现有生产设备条件下，低Ｈ２气氛可以适用于不锈钢带的连续光亮退火。     

不锈钢薄壁焊管光亮退火工艺参数选择

不锈钢薄壁焊管光亮退火工艺参数选择辽宁锦州市焊管厂（锦州１２１０００）樊立奎ＳｅｌｅｃｔｉｏｎｏｆＰｒｏｃｅｓＰａｒａｍｅｔｅｒｓｏｆＢｒｉｇｈｔＡｎｎｅａｌｉｎｇｆｏｒＴｈｉｎ┐ｗａｌＷｅｌｄｉｎｇＰｉｐｅｏｆＳｔａｉｎｌｅｓＳｔｅｅｌＦａｎＬｉｋ...     

304不锈钢冷轧及退火工艺优化的实验研究

以304不锈钢为实验材料,对其退火和冷轧后的性能和组织进行检测和观察,分析了冷轧变形量和退火工艺对304不锈钢组织和性能的影响.结果表明:增大冷轧压下量,退火工艺为1100℃×5 min时获得较高的r值.     

光亮退火对SUS304DQ不锈精密带钢力学性能的影响

采用单向拉伸试验,研究了光亮退火对SUS304DQ不锈精密带钢力学性能的影响,总结出最佳的退火工艺参数。结果表明,随变形量增加,强度指标(HV、σ0.2、σm)上升,塑性指标(δ、φ)降低;对不同加工硬化程度的试样,在低温(300～450℃)下退火10～15min快冷后进行拉伸,其力学性能基本不变,退火软化效果不明显。在全氢环境下,高温(920～1200℃)保持3 min,快冷,该合金组织完全再结晶,且晶粒大小均匀,软化效果明显,表面质量好。通过试验得出,SUS304DQ不锈钢最佳光亮退火工艺为1020～1150℃全氢气氛下保温2 min,快冷。     

大型不锈钢光亮退火机组的技术特点

介绍了国产大型不锈钢光亮退火机组的工艺流程、主要技术参数,以及主要设备的特点和技术亮点,其关键设备如焊接设备、清洗设备和退火炉等均由国内制造。     

304不锈钢免退火直接冷轧工艺研究

分析了热轧304板卷的金相组织及力学性能,结果表明304热轧板卷可以不退火直接进行冷轧。对304热轧板卷进行了免退火直接冷轧试验,轧后冷板经固溶退火,其晶粒度、力学性能及耐晶间腐蚀性能与退火后再冷轧的产品差别不大,符合生产标准要求。因此,实际生产中可以通过优化生产工艺,实现节能降本。     

试论不锈钢光亮退火的若干问题

预测我国不锈钢光亮退火板市场需求 ,分析立式光亮退火炉的工艺目的和设备要求 ,指出建造立式光亮退火炉需特别注意的问题。     

喷丸和退火对304不锈钢晶间腐蚀性能的影响

研究了喷丸和退火对304奥氏体不锈钢抗晶间腐蚀能力的影响。实验结果表明,喷丸处理后试样的耐晶间腐蚀性能比原材料明显降低,腐蚀速度明显增加。经过退火处理后,材料的微观组织结构得到了优化,耐腐蚀性得到显著提高,且随着退火时间的延长,抗晶间腐蚀能力越好。     

NaCl溶液中304不锈钢腐蚀过程的声发射特征

采用声发射技术研究了304不锈钢在0.01和0.05 mol·L-1Na Cl溶液中的腐蚀过程,应用光学显微镜观察了腐蚀前后试样表面形貌。结果表明,0.01和0.05 mol·L-1浓度下,304不锈钢腐蚀产生的声发射起始幅度不同,随时间延长,声发射幅度阶跃,直至达到最终的稳定幅度,这说明随浸泡时间延长,试样腐蚀程度加深。浸泡初期,声发射相对能量较高,声发射相对能量随浸泡时间延长而降低,但仍具有比较明显的相对能量积聚区,0.05 mol·L-1浓度时更为明显,同时其振铃数聚类区多于0.01 mol·L-1。浸泡4 h后,试样表面发生了晶间腐蚀和点蚀。相比0.01 mol·L-1浓度,0.05 mol·L-1下试样表面点蚀数量增多、点蚀孔尺寸增大。     

Microstructure and corrosion resistance of 304 stainless steel electroslag strip cladding

The 304 stainless steel strips were deposited one layer on carbon steel base metal by electroslag strip cladding(ESC) and submerged arc cladding(SAC),respectively.The solidification microstructure of ESC metal was analyzed by the optical microscopy,scanning electron microscope and energy dispersive spectroscopy.The corrosion resistance studies of strip cladding metals were carried out in 10%oxalic acid electrolytic etching test.The results showed that the cladding metal obtained by ESC presented low content of C,high content of Cr and enough alloying element of Ni in the chemical composition.The transition zone of ESC with small width was almost parallel with the base metal,leading to a lower dilution.There are three types of solidification modes(A→AF→FA) occurred in the ESC metal due to the decrease of cooling rate and degree of dilution from the transition zone to the top of ESC metal.As a result,the microstructure of ESC metal exhibited mainly austenite with a small amount offerrite,contributing to achievement of better corrosion resistance.     

再结晶退火温度对含Cu铁素体抗菌不锈钢耐蚀性的影响

通过金相分析、FeCl₃点腐蚀试验、点蚀坑形貌观测、极化曲线测试等方法,研究了再结晶退火温度对含Cu铁素体抗菌不锈钢耐蚀性的影响。结果表明:在860～980 ℃范围内保温5 min,含Cu铁素体抗菌不锈钢再结晶程度逐渐提升,耐蚀性先增强后减弱,最佳再结晶退火温度为900 ℃。含Cu铁素体抗菌不锈钢在酸性FeCl₃溶液中点蚀坑呈开放式,随再结晶退火温度的升高,点蚀坑面积及深度减小,在980 ℃退火时其数量明显增多。     

Mechanism of improved corrosion resistance of type 304l stainless steel,nitric acid grade,in nitric acid environments

Materials for critical components in nuclear fuel reprocessing plants are required to have low corrosion rates and long designed life because access for repairs is not possible. Stainless steel type 304L, nitric acid grade (NAG), is the new material suitable for such applications. It has guaranteed low corrosion rates and is not susceptible to intergranular corrosion (IGC) in nitric acid environments. The corrosion behavior of type 304L stainless steel, NAG, and type 304L stainless steel, commercial purity (CP), in nitric acid environments is investigated in detail. Studied are: microstructural mapping in the three directions (longitudinal, long transverse, and short transverse), effect of sensitization heat treatment, resolution annealing and sensitization heat treatment for the as-received and cold-worked samples of the two varieties on the resultant microstructures. The anodic polarization characteristics along the three directions for both varieties in 1N HNO₃ are compared. The susceptibility of both varieties to end grain corrosion in 9N HNO₃ + 1 g Cr⁺⁶/liter boiling solution is assessed, and microstructural examination of the exposed sample is carried out to compare the degree of end grain corrosion. Their susceptibility to IGC due to segregation of impurity elements to grain boundaries is also compared. It is shown that controlled microstructure (fine grain size, retained cold work, and discrete precipitation at grain boundaries) along with controlled chemical composition is responsible for improved corrosion resistance of the NAG variety. The NAG variety has much less susceptibility to corrosion along the long- and short-transverse directions and, therefore, less susceptibility to end grain corrosion. The means and consequences of controlling chemical composition are also discussed.     

黄铜与304不锈钢的电阻软钎焊封装工艺

针对某热量表的温度传感器中由于尼龙成分的存在导致其构成材料黄铜和304不锈钢不能在高温下焊接的问题,采用电阻软钎焊的低温连接方法进行焊接试验,以实现密封连接效果. 结果表明,在0.3 MPa的焊接压力下,当焊接电流设定为26 kA时,以双层Sn-Pb箔片为钎料的焊件进行的试验效果良好,达到了可靠的连接,且黄铜中心尼龙成分未受到焊接温度的影响而损坏. 在扫描电镜下观察到钎料与不锈钢和黄铜均发生了表面扩散. 将焊接后的样品置于水中进行密封性试验,结果显示焊缝区域实现了可靠地连接,达到了密封防水效果.     

Rhodanine azosulpha drugs as corrosion inhibitors for corrosion of 304 stainless steel in hydrochloric acid solution

The effect of rhodanine azosulpha drugs on the corrosion behaviour of 304 stainless steel in 1.0 M hydrochloric acid solution as corrosive medium has been investigated using weight loss and potentiostatic polarization techniques. Some corrosion parameters such as anodic and cathodic Tafel slope, corrosion potential, corrosion current, exchange current densities, surface coverage and inhibition efficiency were calculated. The polarization measurements indicated that the inhibitors are of mixed type and inhibit corrosion by parallel adsorption on the surface of steel due to the presence of more than one active centre in the inhibitor molecule. The adsorption is obeyed Langmuir adsorption isotherm. The activation energy and thermodynamic parameters were calculated at different temperature.     

表面喷丸压力对304不锈钢应力腐蚀敏感性的影响

采用3种表面喷丸压力对304不锈钢板状试样进行强化处理。通过扫描电子显微镜分析了强化层的厚度和晶粒细化程度,采用显微硬度计检测了表层显微硬度分布。通过5%NaCl溶液中慢应变速率拉伸试验,比较了0.25、0.30和0.40 MPa喷丸压力处理后试样的应力腐蚀敏感性。结果表明：表面喷丸强化处理可以细化试样表层晶粒,提高硬度;随着喷丸压力的升高,试样表层晶粒层厚度增大,表面硬度提高,应力腐蚀敏感性指数降低。     

热处理工艺对含铜不锈钢00Ni40Cu3耐蚀性能的影响

在满足元素间混合热的要求下,提出了稳定固溶体团簇模型[CuNi12][NiFe12]1.66,设计出面心单相不锈钢00Ni40Cu3（Ni39.4Fe57.7Cu2.9at%）,并且研究了热处理工艺对合金组织与性能的影响。结果表明,退火工艺为800℃保温30 h再升温至1000～1050℃保温2 h后水淬的条件下,合金具有面心单相结构,在3.5%NaCl溶液中具有良好的耐蚀性能,自腐蚀电位约为-0.260 V,自腐蚀电流约为3.000×10-7 A/cm2,与同种条件下304（0Cr18Ni9）和316（0Cr17Ni12Mo2）不锈钢比较,耐腐蚀性能相当。