摘要
目的提高碳钢耐液态Pb-Bi耐腐蚀性能。方法采用熔钎焊的方法,对6061铝合金和Q235钢进行搭接焊,焊后采用微弧氧化技术在焊接接头制备微弧氧化陶瓷层,将其放入350℃的高温液态Pb-Bi中进行300h静态腐蚀试验。结果选用钨极氩弧焊机,用ER4043焊丝作为钎料,通过调节焊接参数,在焊接电流为85 A、焊接速度为140 mm/min的参数下,铝层与Q235钢的结合强度达到182 MPa,金属间化合物厚度为7.3μm。在2 g/L KOH+4 g/L Na2Si O3·9H2O的电解液中进行微弧氧化试验,放电孔洞直径和数量随着电流密度的增大而增加。通过对比发现,在10A/dm2下生成的氧化膜层厚度适宜,同时致密性较好,陶瓷层由γ-Al2O3和α-Al2O3组成。经过静态腐蚀后,Q235碳钢母材试样表面被明显腐蚀,而Q235钢微弧氧化后的试样则有较好的耐腐蚀性能,其中10 A/dm2电流密度参数下制得的氧化膜层耐蚀性能最优。结论微弧氧化陶瓷膜层可显著提高材料在高温液态Pb-Bi合金中的耐腐蚀性能,且膜层致密性和厚度会影响其对材料的保护作用。
The work aims to improve the corrosion resistance of carbon steel in liquid Pb-Bi.The 6061 aluminum alloy and Q235 steel were lap welded by fusion brazing method.After welding,micro-arc oxidation technology was used to prepare micro-arc oxidation ceramic coating on the welded joint.Then the micro-arc oxidation samples were put into 350℃liquid Pb-Bi for 300 h static corrosion test.The tungsten argon arc welding machine was used,and the ER4043 welding wire was selected as the brazing material.By adjusting the welding parameters,the bonding strength of the aluminum layer and the Q235 steel reached 182 MPa and the intermetallic compound thickness was 7.3μm under the parameters of welding current of 85 A and welding speed of 140 mm/min.Micro-arc oxidation experiments were carried out in 2 g/L KOH and 4 g/L Na2SiO3·9H2O electrolytes.The diameter and number of discharge holes increased with the increase of current density.By comparison,it was found that the thickness of the oxide coating formed at 10 A/dm2 was suitable and the compactness was good.The ceramic coating was composed ofγ-Al2O3 andα-Al2O3.After static corrosion,the surface of Q235 carbon steel base material was obviously corroded,while Q235 steel sample after micro-arc oxidation had better corrosion resistance.The corrosion resistance of oxide coating obtained under 10 A/dm2 current density was the best.The micro-arc oxidation ceramic coating can significantly improve the corrosion resistance of the material in high temperature liquid Pb-Bi alloy,and the compactness and thickness of the coating will affect the protective effect on the material.
作者
朱强
陈文彬
雷玉成
赵军
ZHU Qiang;CHEN Wen-bin;LEI Yu-cheng;ZHAO Jun(Jiangsu University,Zhenjiang 212013,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2019年第2期193-199,共7页
Surface Technology
基金
国家自然科学基金青年基金项目(51505197)~~
关键词
熔钎焊
微弧氧化
陶瓷层
电流密度
液态Pb-Bi腐蚀
fusion brazing
micro-arc oxidation
ceramic layer
current density
liquid Pb-Bi corrosion
