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在常规锆合金管材酸洗工艺参数下,研究了Zr-4合金管材在酸洗过程中内径尺寸、取样位置、冲水温度以及缺陷深度对氟残留的影响规律,并利用有限元法(FEM)对实验结果进行了理论分析。结果表明:随着Zr-4合金管材内径的增大,管材内表面的氟残留逐渐增大;Zr-4合金管材头部、中部及尾部的氟残留基本保持一致;随着冲水温度的升高,Zr-4合金管材内表面氟残留降低;Zr-4合金管材的缺陷深度与氟残留无明显的对应关系。 相似文献
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研究了Zr-4合金管材酸洗处理过程中,酸洗去除量、酸水转换时间、冲水时间及酸洗次数对管材氟残留量的影响,并基于径向基(RBF)人工神经网络法建立了Zr-4合金管材酸洗工艺与氟残留的神经网络模型。结果表明:冲水酸水转换时间和冲水时间对氟残留量均有影响,且酸水转换时间的影响更为显著;氟残留量与酸洗次数无明显对应关系。Zr-4合金酸洗工艺的RBF神经网络模型结构为3-5-1,实际值与模拟值的相对误差为9.2%。该神经网络模型具有较高的可靠性,可为Zr-4合金酸洗工艺参数的优化提供参考。 相似文献
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在卧式连续喷淋酸洗机组上,利用原设备和H2SO4+(HNO_3+HF)酸洗液技术酸洗双相不锈钢中厚板,酸洗后表面出现浅灰色、下表面辊印缺陷。针对这些缺陷,以S32205双相不锈钢板为代表牌号,论述一种两段式混酸(HNO_3+HF)液酸洗方法,开展了两段式混酸(HNO_3+HF)液酸洗方法的实验室、工业化工艺试验和研究,并对原卧式喷淋酸洗生产线进行了技术改造。应用两段式混酸(HNO_3+HF)液工艺技术酸洗S32205钢板,在预先酸洗工艺段,混酸液HNO_3质量浓度为180g/L、HF质量浓度为90g/L,混酸液温度为43℃;在最终酸洗工艺段,混酸液HNO_3质量浓度为265g/L、HF质量浓度为56g/L,混酸液温度为43℃,一次酸洗合格率达到95%以上。从技术上解决了双相不锈钢中厚板酸洗后表面出现的浅灰色、下表面辊印缺陷,酸洗后的钢板表面呈银白色,色泽均匀,满足了双相不锈钢板产品标准关于表面质量的要求。 相似文献
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在原卧式连续喷淋酸洗机组,应用H_2SO_4+(HNO_3+HF)酸洗液技术、一段式混酸(HNO_3+HF)酸洗液技术酸洗不锈钢中厚板304系列产品,出现表面色差、上表面辊印缺陷。针对这些缺陷,以304系列不锈钢中厚板为代表,论述两段式混酸(HNO_3+HF)液酸洗方法,开展两段式混酸(HNO_3+HF)液酸洗方法的工艺试验和研究,并对原卧式喷淋酸洗生产线进行技术改造。采用两段式混酸(HNO_3+HF)液工艺技术,酸洗304系列不锈钢中厚板。在预先酸洗工艺段,混酸液HNO_3为220 g/L、HF为45 g/L,混酸液温度为46℃;在最终酸洗工艺段,混酸液HNO_3为280 g/L、HF为20 g/L,混酸液温度为41℃。酸洗后的钢板表面银白色,一次抛丸酸洗合格率90%以上。 相似文献
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《钢铁研究学报(英文版)》2016,(8):778-783
To shorten the time required for the pickling process and to enhance the quality of ferritic stainless steel plates,the effects of oxidants including hydrogen peroxide(H2O2),potassium permanganate(KMnO4),and potassium chlorate(KClO3)on the pickling behavior in HCl-based electrolyte as well as the surface quality of hot-rolled and blasted 430 stainless steel(430-SS)were studied.Experiments were conducted using mass-loss tests,microstructure analyses,potentiodynamic polarization curves,and electrochemical impedance spectroscopy measurements.The results showed that the addition of oxidants substantially accelerated the pickling process of 430-SS by enhancing the cathodic reaction rate and reducing the charge transfer resistance.In electrolytes comprising 5-8mass% HCl at a temperature of 40-60 ℃ and at the same concentration within the range from 0to 2mass%,H2O2 was demonstrated to be superior to KMnO4 and KClO3in accelerating the pickling process.The surface quality of 430-SS pickled in the presence of H2O2 was better than those of specimens pickled in the presence of KMnO4 and KClO3 when the removal of the oxide layer,intergranular corrosion,and surface roughness were collectively considered.When 1mass% H2O2 was added,the mass loss rate of 430-SS was increased by 629%and no residual oxide layer or intergranular corrosion was observed on the surface of the steel;in addition,the roughness was only 1.7μm.H2O2 was determined to be a better oxidant than KMnO4 and KClO3 when the pickling process,surface quality,solution recycling,and environment protection were considered as a whole. 相似文献
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为了提高CSP产线热轧酸洗板的洁净度与综合性能,研究了CSP工艺下QSTE500TM(汽车结构用热轧酸洗板)冶炼过程和热轧卷中的夹杂物。冶炼过程中夹杂物的变化路线是Al2O3-SiO2-MnO→Al2O3→MgO-Al2O3-CaO-CaS→Al2O3-CaO-CaS。LF钙处理前到中间包阶段,钢液中夹杂物总量基本不变,约为200 μm2/mm2。热轧卷中夹杂物总量约是钢液中的2倍,组成主要是较大尺寸的MgO-Al2O3-CaO-CaS、小尺寸的TiN析出物以及中等尺寸的Al2O3-CaO-TiN复合夹杂。随着氮含量的增加,热轧卷中夹杂物总量增加、小尺寸夹杂物分布均匀,10 μm以上的夹杂物在卷宽1/4处分布最多。由于选分结晶的作用,复合夹杂中TiN的质量分数在10%~100%之间变化,随着TiN含量的升高,夹杂物尺寸逐渐变小。CSP工艺下热轧卷中第二相析出物更均匀,有利于产品最终的力学性能。综合考虑过程控制能力和产品性能需求,建议CSP热轧酸洗板严格控制连铸保护浇铸,氮质量分数小于0.006 0%。 相似文献
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为去除热轧不锈钢板表面的氧化层与贫铬层,钝化基体,改善表面质量,在热轧退火后需进行酸洗处理。介绍了热轧不锈钢板表面氧化层和贫铬层的组成与结构特征及其对酸洗过程的影响,并对热轧不锈钢板的酸洗体系设计和酸洗工艺开发进行了阐述。中国热轧不锈钢板普遍采用前处理(机械除鳞、中性盐电解等)→硫酸(电解)预酸洗→硝酸-氢氟酸终酸洗的酸洗工艺,旨在通过前处理和预酸洗去除大部分的氧化层,在终酸洗阶段去除残余氧化层及贫铬层,同时实现基体钝化。目前,热轧不锈钢板的酸洗工艺存在酸洗效果不稳定、贫铬层去除不完全、局部腐蚀较为严重等问题,且会产生不同程度的环境污染问题。应该根据不同钢种不同退火工艺条件下的表面氧化层与贫铬层的性质与分布特征,研究开发相应的酸洗体系和酸洗工艺。热轧不锈钢板的环保型酸洗新工艺具有广阔的发展前景。 相似文献
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B. S. Covino J. V. Scalera T. J. Driscoll J. P. Carter 《Metallurgical and Materials Transactions A》1986,17(1):137-149
The dissolution behavior of type 304 stainless steel was studied in typical pickling environments in an effort to reduce the
unnecessary loss of the critical metals nickel and chromium during the pickling process. Dissolution rates were determined
for a 90-minute exposure to HNO3/HF solutions ranging from 0.8 M to 3.5 M HNO3 and 0.5 M to 2.6 M HF at 30°, 50°, 70°, and 90 °C and containing 0 to 0.21 M dissolved Fe, Cr, or Ni. Dissolution rates increased
as a function of increasing HNO3 concentration from 0.4 M to 1.5 M HNO3, decreased at higher HNO3 concentrations, and increased with increasing HF concentration. Experiments to determine the effect of temperature on the
dissolution reaction gave a lower activation energy for solutions with higher HNO3 concentrations. The dissolved Fe and Cr decreased the dissolution rate of 304 stainless steel, while dissolved Ni had essentially
no effect. The Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) studies of films resulting from
exposure to several HNO3/HF solutions indicated that the fluoride did not penetrate the thin nonprotective films but remained on the outer surface
of the film. The scanning Auger microscopy (SAM) studies indicated that the fluoride was uniformly distributed over the surface.
Both the dissolution and surface studies are consistent with a dissolution process which is controlled by reactions occurring
either in solution or at the film-solution interface. 相似文献
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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。 相似文献