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1、摘要随着耐磨堆焊技术的发展如新型耐磨堆焊药芯焊丝的出现,原有的焊剂品种已不能满足需求。开发适用于耐磨堆焊的新型焊剂,是目前焊接材料研究领域内的热点。本文针对耐磨堆焊的特点,开发出了渣系为Al2O3-CaF2-CaO-MgO-SiO2,碱度为1.7的烧结焊剂。该焊剂配合马氏体不锈钢堆焊用药芯焊丝,焊接工艺性能良好,堆焊层焊态硬度≥45HRC。本文通过对耐磨堆焊工艺的研究,确定了堆焊烧结焊剂应为碱性焊剂,以使堆焊过程中对合金的氧化较小。讨论了熔渣的膨胀系数、熔点、粘度、表面张力与焊接工艺性能的关系,确定了合理的焊剂的成分范围。然后通过堆焊试验
2、,找出了一组工艺性能良好的焊剂配方。在焊剂配方基本满足工艺性能条件下,分析不同成分对焊接工艺性能的影响规律,并对焊剂进行改进。本文研究了成分中MgO、Al2O3、CaF2、CaCO3、MnO以及ZrO2对焊接工艺性能的影响。其中,少量CaCO3分解出的CO2能促进熔池金属的搅拌作用,从而有利于熔池脱气;少量ZrO2则能大大提高碱性焊剂的脱渣性能。比较了作为焊剂原料,烧结镁砂和电熔镁砂的区别,以及二者对工艺性能的影响。探讨了在烧结焊剂中加入HJ431的可行性,并通过试验进行验证。从堆焊层的硬度试验及金相组织可知,新型耐磨堆焊烧结焊剂配合马氏
3、体不锈钢药芯焊丝能获得高的焊态硬度和较均匀的组织,具有较好的耐磨性能。关键词:耐磨堆焊;烧结焊剂;碱度;焊接工艺性能;渣系IAbstractItisveryvaluabletousebuild-upweldingtorepairmachineswhichinactivatedbyattrition.Alongwiththehardfacingtechnology’sdevelopment,suchasnewkindsofflux-coredweldingwire’sappearance,theoriginalfluxes’varietyh
4、asnotbeenabletomeettheneed.Developingnewfluxforhardfacing,nowisthehotspotintheweldmaterialresearcharea.Inviewofhardfacing’scharacteristics,anewkindofagglomeratedfluxdeveloped.TheslagsystemofnewagglomeratedfluxisAl2O3-CaF2-CaO-MgO-SiO2,anditsalkalinityis1.7.Whencordinating
5、withmartensiticstainlesssteelflux-coredweldingwire,theagglomeratedfluxcanmaketheprocessingpropertyofhardfacinggood.Thehardnessofhardfacing’soverlayishigherthan45HRC.Wefoundthatthefluxhavetobealkalineflux,inordertoreducetheoxidationofalloy.Thisarticaldiscussestherelationsb
6、etweenweldingprocessingpropertyandslag’sphisycalfeatureswhichincludingexpansioncoefficient,meltingpoint,viscosityandsurfacetensile.Thediscussionhelpsustogetaproperrangeofrawmaterial’srate.Basedonexperimentsofbuild-upwelding,acompoundingisfound,whichhasbestweldingprocessin
7、gproperty.Thisarticledidresearchontherelationsbetweenthecomponentsandtheweldingprocessingproperty,theresearchedcomponentsareMgO,Al2O3,CaF2,CaCO3,MnOandZrO2.Asrawmaterialforagglomeratedflux,magnesiteclinkerisdifferentfromfusedmagnesite,wecompairedtheirweldingprocessingprop
8、erties.WediscussedthefeasibilitytouseHJ431toreplacemanganesemineralsinagglomeratedflux,anddidexp