加氢设备的异种钢焊接和堆焊

DISSIMILAR STEEL WELDING AND OVERLAY WELDING IN HYDROGENATION EQUIPMENT

加氢反应系统的设备存在大量异种钢焊接和堆焊。异种钢焊接本身存在材质性能上的不均衡、受热膨胀不均匀等缺点。界面应力、界面H浓度和堆焊时的碳迁移是导致加氢设备堆焊层氢剥离关键因素。堆焊方法会影响界面金相组织和氢剥离的倾向,因此如何正确理解异种钢焊接的特点,准确选择焊接材料以及更合理的使用焊接方法等,是值得讨论的问题。经验表明:对于加氢设备,单层堆焊采用带极埋弧堆焊、双层堆焊采用带极埋弧自动堆焊加带极电渣自动堆焊的方案是合理可行的。

There is plenty of dissimilar steel welding and overlay welding in hydrogenation reaction system. Dissimilar steel welding has the defects of unbalanced material properties and uneven thermal expansion. Interfacial stress, interface H concentration and carbon migration during surfacing are the key factors leading to hydrogen-induced disbanding of the hydrogenation equipment surfacing layer. The overlay welding method will affect the interface metallographic structure and the tendency of hydrogen-induced disbanding. Such issues as how to understand the characteristics of dissimilar steel welding correctly, how to select welding materials accurately and how to select more reasonable use of welding methods are worthy of discussion. Experiences have shown that for hydrogenation equipment, it is reasonable and feasible to adopt submerged arc overlay welding for single-layer overlay welding and adopt automatic submerged arc overlay welding plus automatic electro slag overlay welding for two-layer overlay welding.