共查询到16条相似文献,搜索用时 125 毫秒
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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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为快速反馈不锈钢带退火质量,减少退火工艺调整时间,降低取样费用,根据奥氏体不锈钢和铁素体不锈钢的特点,用超声波和剩磁法在线检测退火后晶粒尺寸,有效控制连续退火酸洗线带钢退火性能,目前已在国内外多条冷轧不锈钢连续退火酸洗线上得到了成功应用。 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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以12%Cr铁素体不锈钢为研究对象,研究了不同退火方式、退火工艺对12%Cr铁素体不锈钢热轧板和冷轧板组织、力学性能、耐腐蚀性能、成形性能的影响。结果显示,12%Cr铁素体不锈钢高温下存在铁素体—奥氏体相变过程,在双相区退火快冷后有马氏体组织生成。通过在热退过程中引入奥氏体相变和马氏体相变,可以显著细化最终产品晶粒,提高最终冷轧产品的强度、硬度,同时保持材料耐腐蚀性能不变。该工艺生产的产品可以适用于高强度的应用场合,打破了传统12%Cr铁素体不锈钢热轧后只能采用罩式炉退火的束缚,针对产品的最终用途可以采用不同的退火方式和退火工艺进行生产。 相似文献
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介绍了新建热轧不锈钢带钢退火酸洗线的生产工艺流程、关键设备和技术特点。退火炉为两通道,天然气和煤气可以互相切换,技术优势明显;抛丸机配有24套抛丸器,保证了带钢酸洗前的高效除鳞;酸洗段配有研磨刷洗机,可以减轻酸洗段负担,降低带钢酸洗后表面粗糙度,提高产品品质;酸槽底部安装小喷嘴,能耗小,并可提高酸洗效果。 相似文献
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不锈钢冷轧退火酸洗机组需要对带钢进行酸洗处理以去掉带钢表面氧化铁皮,通过对混酸酸洗产生的废酸进行树脂吸附,去掉可溶性金属离子,自由酸重新循环利用,以减少废酸排放,降低生产成本,提高酸洗产品质量。 相似文献
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316L不锈钢为常用的耐蚀合金材料,然而其在海洋大气环境服役时易遭受点腐蚀而发生失效。通过点腐蚀速率、临界点蚀温度、点蚀电位、极化曲线测试等评价方法,对经过不同表面处理(光亮退火、抛光、酸洗钝化)后的316L不锈钢的耐点蚀性能进行测试分析。结果表明,不同表面处理对316L不锈钢的临界点蚀温度影响不大,但会使点腐蚀速率、点蚀电位有所差异;在测试条件下,抛光及酸洗钝化均可有效提高316L不锈钢的耐点蚀性能,其中酸洗钝化态的耐点蚀性能最好,因此建议对海洋工程用316L不锈钢产品在使用前进行酸洗钝化处理。 相似文献
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Peiyang Shi Haonan Shi Chengjun Liu Maofa Jiang 《Canadian Metallurgical Quarterly》2018,57(2):168-175
Oxide layer formed on stainless steel surface can result in a decrease in surface quality. Thus, it must be removed. In this paper, we investigated the effect of different pickling processes on removal of the oxide layer. Ferritic stainless steel was used as raw material. After it received annealing treatment, the components and structure of the oxide layer formed on its surface were studied. Then, the annealed stainless steel was pickled in hydrochloric acid solution system and mixed acid solution system, respectively. Results are as follows. The oxide layer on stainless steel surface has a thickness of 15–35?μm. With increase in hydrochloric acid concentration in hydrochloric acid pickling solution, the weight loss rate of stainless steel increases and is always greater than that in mixed acid pickling system. In addition, the surface of the stainless steel pickled in hydrochloric acid is smoother than that pickled in mixed acid. Furthermore, compared with channels in the oxide layer created during mixed acid pickling, those created during hydrochloric acid pickling are more, leading to shorter removal time. These results are important for increasing the pickling efficiency and improving the surface quality of stainless steel. 相似文献
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Oxide formation during production annealing and the subsequent pickling response in mixed acid have been studied. The aims were to characterise the oxides formed and to understand how the pickling mechanism and kinetics are affected by the nature of the oxide. Totally, eight different versions of the austenitic stainless steel grades AISI 301, 304L and 309L were studied, all annealed in production lines. Cold rolled oxides (formed during annealing) are thin (< 1 µm), dense and formed in a multilayered manner. Hot rolled oxides (formed during reheating, hot rolling and annealing) are thicker (>1 µm) and more heterogeneous in thickness and composition. The dissolution rate of the chromium depleted layer (CDL) under the oxide is the most important factor for the overall pickling rate. The permeability of acid through the oxide and the tendency of the oxide to spall are also important factors affecting the pickling kinetics. The dense oxide formed on cold rolled materials can to some extent hinder the acid to reach the CDL. The oxides on hot rolled materials are porous and do not provide such a barrier but they are thicker and thereby more difficult to remove. Shot‐blasting prior to pickling of the hot rolled materials improves the pickling performance because it thins the oxide, improves the permeability and increases the tendency of the oxide to spall during the pickling step. 相似文献