热门关键词：济南彩钢板 | 济南复合板 | 济南彩钢瓦 | 济南c型钢 | 济南钢结构 |
The base course of composite steel plate shall meet the requirements of joint strength and stiffness, and the cladding shall meet the requirements of corrosion resistance. In order to ensure that the composite steel plate does not lose its original comprehensive properties, the base layer and the composite layer must be welded separately. What are the welding difficulties and solutions of clad steel plate?
1. When welding base course
Due to the large thickness of the plate, the welded joint bears a large restraint stress; Under the action of welding thermal cycle, martensite hardening structure is easy to produce in the heat affected zone, which increases the hardness and brittleness of the welded joint and significantly reduces the toughness and plasticity. These factors will lead to welding cracks.
In order to effectively prevent the occurrence of welding cracks, the following measures can be taken: select low hydrogen electrode; The welding rod shall be dried as required before use; Carefully clean the water, oil, rust and other impurities on the groove surface; Select reasonable welding process parameters, such as preheating before welding, slow cooling after welding, multi-layer and multi pass welding, and control interlayer temperature; Choose proper welding sequence to reduce welding stress, etc.
2. When welding cladding with stainless steel electrode (a002)
It is easy to melt the base layer, which dilutes the composition of weld metal, thus reducing the plasticity and corrosion resistance of weld metal, and significantly increasing the brittleness of fusion zone. Therefore, when welding cladding, we must control the welding line energy and adopt multi-layer and multi pass welding to reduce the welding penetration.
3. When welding the transition layer with austenitic steel electrode (A302)
The weld is easy to produce hot cracks. At the same time, the carbon migration process will occur in the transition zone: that is, the carbon will be transferred from the low chromium base to the high chromium stainless steel deposited metal. Therefore, a high hardness carburizing layer and a low hardness decarburizing layer will be formed at the junction of the base and the composite layer,
Cause embrittlement (or softening) in the fusion zone, reduce the lasting strength, and easily produce fatigue cracks. Small diameter electrode should be used for fast multi pass welding. If necessary, cold water can be poured to accelerate cooling, prevent the formation of decarburization layer, and make the welded joint have high strength and toughness.
Jinan clad steel plate factory believes that the key to the assembly and installation of clad steel plate containers is welding, and the key to welding is the welding of transition layer. Therefore, it is necessary to master the above welding points of clad steel plate.
The welding difficulties and solutions of clad steel plate are the above contents. I hope to help you. For more information, please come to our website http://www.jnjgcg.com Pay attention to understand.