Iron Separation Equipment Filter Box Ferritic Stainless Steel Welded Structure, Process And Properties Research

Currently iron separation equipment widely used in metal processing, removing ironfrom non-metallic ore, sewage treatment,etc.,but domestic iron separation equipmentshave emerged thin rod filter box fracture phenomena,it seriously affect industrialproduction cycles, yield and quality of concentrate. Solving the problem of thin rodsFilter box fracture phenomena becomes magnetic industry pressing problems, with athin rod filter box mineral separation of iron ore,it plays an important role inimproving the iron ore concentrate quality for the country,and increasing therecovery rate of iron ore, expansion ore exploitation and the promotion andapplication of magnetic separation equipment. This thesis is for filter box of ironseparation equipment in service, a large number of ferritic stainless steel rods fracturephenomena during short periods.Firstly, by metallographic analysis, scanning electron microscopy (SEM) morphologyand EDS composition analysis, this thesis explores the failure mechanisms of filterbox welded joints in service; Secondly, by tensile test,acid corrosion test,electrochemical corrosion test, magnetic test, Comprehensive study the mechanicalproperties,corrosion resistance,magnetic properties of the original materials0Cr13and new materials Cr10NiTiMo,verify the feasibility of the use of new materials;thenpropose process measures to reduce the filter box welding deformation, improvedfilter box assembly precision;and research the influence of processing parameters onthe microstructure of welded joint by joint metallographic analysis;and explorewelding process parameters on the influence of weld by test,to provide test data foraccess to qualified weld; Finally, inspect life of the filter box in industrialapplications.The conclusions were as follows:1) The failure mechanisms of ferritic stainless steel rods welds while serving in acidicmedia is stress corrosion cracking. Analysis from the ferritic stainless steel rods weldforce state, it is only to withstand the residual stresses produced during the welding (the weld is more, residual stress is larger), but also to withstand the electromagneticforce; from the weld organizations of ferritic stainless steel to consider, coarse grainin heat affected zone area is the weak link in the entire welded joints, it is generallybreak at this location.2) Through experiment comparing,0Cr13and Cr10NiTiMo ferritic stainless steelshave the roughly same mechanical properties, while Cr10NiTiMo (or Cr11NiTiMo)has more excellent acid corrosion resistance and magnetic properties than0Cr13.3) Through to redesign the filter box structure, to remove splice welding processes,increasing support plate structure, can effectively reduce welding deformation of thefilter box parts; Other, by taking the welding process measures, such as the use ofpre-deformation, changing the welding sequence and the welding direction, canfurther control the welding deformation and reduce welding stress.4) In the swivel’s partition plates welding process, by using welding fixture, to ensurepositional accuracy and dimensional accuracy of the partition plates, thus avoid theferritic stainless steel rods damage caused by the filter box assembly difficult.5) Research by process parameters on the microstructure of welded joints showed thatwhen the ferritic stainless steel rod welding after annealing, grain coarsening tendencyweakened in heat affected zone. Other welding parameters have an impact on thegrain size of coarse grain area, but not significantly.6) Fatigue test showed that by using Cr10NiTiMo (or Cr11NiTiMo) as ferriticstainless steel rods material, the use of new structural design and the use of variouscontrol welding deformation process measures, the weld fatigue life of the media stickis six times higher than the original.7) Improved filter boxes have been used in metal processing and removing impuritiesfrom non-metallic mineral and other industries, from the application point of view, thefilter boxes have advantages of improved separation index, long life, and not easy toto clogging.