钢焊接研究——设计

淮阴工学院毕业设计（论文）--I16Mn钢焊接研究摘要16Mn钢是具有高强度、高韧性和耐腐蚀等优良特性的低合金高强钢，是我国低合金高强钢中用量最多、产量最大的钢种，广泛用于制造桥梁、船舶、车辆、锅炉、高压容器、输油输气管道、大型钢结构等。鉴于16Mn钢在我国工业和国民经济建设中的重要性，而16Mn钢的焊接又是16Mn钢应用中必不可少的一道工艺技术,因此16Mn钢的焊接进行研究对实践应用意义重大。本课题采用焊条电弧焊对16Mn钢进行焊接，分析焊接接头的组织和性能的变化；并对得到的焊接接头进行正火处理，分析热处理前后焊接接头组织和性能的变化。结果表明，焊接接头焊缝区组织为柱状晶；熔合区为粗大晶粒；过热区为魏氏组织；完全结晶区为细小的铁素体和珠光体；不完全结晶区一部分为细小的铁素体和珠光体，一部分为粗大的铁素体。由于熔合区粗大晶粒和过热区魏氏组织的存在使得16Mn钢焊接接头可能存在冷裂纹和热影响区脆化等缺陷。所以对其进行焊后正火处理，热处理后的焊接接头晶粒明显比未热处理过的要细小，组织结构更加均匀。硬度也相应的有所升高。因此，热处理可以改善焊接接头的组织，并提高其性能。本课题研究的16Mn钢焊条电弧焊工艺、焊接接头组织和性能以及焊后热处理工艺可为实践生产中16Mn钢的焊接提供参考。关键词：16Mn钢；焊条电弧焊；焊接接头；组织和性能；热处理阙建龙：16Mn钢焊接研究--IIWeldingResearchof16MnSteelAbstract16Mnsteelisalowalloyhighstrengthsteelwhichhashighstrength,hightoughnessandcorrosionresistanceandotherexcellentcharacteristics.IthasthelargestamountandthelargeststeelproductionamongthelowalloyhighstrengthsteelinChina.Itiswidelyusedinmanufactureofbridges,ships,vehicles,boilers,pressurevessels,pipelines,largesteelstructure.Inviewoftheimportanceof16Mnsteelinoursindustryandnationaleconomy,also16Mnsteelweldingisanessentialtechnology,sotheweldingofsteel16Mnstudyissignificantforpracticalapplication.Inthisissue16MnsteelwasweldedbySMAW,thechangesweldedjointwereanalyzedintheorganizationandperformance;weldedjointswereobtainedbynormalizingprocessing,andanalyzedthechangesoftheorganizationandperformancebetweenbeforeandafterheattreatment.Theresultsshowthattheweldzoneisthecolumnarcrystal;fusionzoneiscoarsecrystal;hotareaisthewidmanstattenstructure;completelycrystallineregionistheferriteandpearlite;onepartofincompletecrystallineregionisthesmallFerriteandPearlite,anotheristhecoarseFerrite.Thecoarsecrystalofthe16Mnsteelweldedjointfusionzoneandthewidmanstattenstructureofthe16MnsteelweldedjointhotareaastheresultofColdcrackingandHAZ.Soitwasprocessedbynormalizingafterwelding,weldedjointsafterheattreatmentweresignificantlyhigherthanthegrainisnotheattreatedtosmallandmoreuniformstructure.Hardnesswasincreasedaccordingly.Therefore,heattreatmentofweldedjointscanimprovetheorganizationandimproveitsperformance.Researchof16Mnsteel'sSMAW,microstructureandpropertiesofweldedjoints,heattreatmentafterweldingcanbeusedasareferenceoftheweldingof16Mnsteelinpractice.Keywords:16Mnsteel;electrodearcwelding;weldedjoint;microstructureandproperties;heattreatment淮阴工学院毕业设计（论文）--III目录引言........................................................................................................................................1第1章绪论........................................................................................................................21.1背景与意义....................................................................................................................21.2发展概况........................................................................................................................21.3来源与内容....................................................................................................................3第2章焊接理论知识............................................................................................................42.1焊接性及其实验评定....................................................................................................42.1.1焊接性及影响因素.................................................................................................42.1.2焊接性评定原则及方法.........................................................................................52.2焊接接头及组织和性能................................................................................................72.2.1焊接接头的概念.....................................................................................................72.2.2焊接接头的基本形式.............................................................................................82.2.3焊接接头的设计要求...........................................................................................102.2.4坡口的基本形式...................................................................................................102.2.5焊接接头特性.......................................................................................................112.3焊条电弧焊..................................................................................................................132.3.1焊条电弧焊概述...................................................................................................132.3.2焊接设备及辅助工具...........................................................................................132.3.3焊条电弧焊基础...................................................................................................162.3.4焊条电弧焊工艺参数...........................................................................................182.3.5焊条电弧焊的基本操作技术...............................................................................192.3.6常见的焊条电弧焊缺陷及防治措施...................................................................21第3章实验过程..................................................................................................................223.116Mn的焊接......................................................................