简介：采用金相组织观察、力学性能测试和统计分析等手段,研究了成品退火工艺对Φ5mmTP2内螺纹铜管微观组织和力学性能影响规律。结果表明:Φ5mmTP2内螺纹铜管退火温度为470~480℃时,铜管组织细小、均匀,同时能获得较高塑性和较高强度;490~500℃时,铜管晶粒尺寸、力学性能波动大;510~520℃时,铜管组织易粗大。Φ5mmTP2内螺纹铜管在470℃退火时,晶粒尺寸随退火时间的规律变化为d=0.0008t3-0.062t^2+1.7t-1.3,保温21min时,铜管再结晶基本完成,保温时间为28~31min时,铜管组织状态和综合力学性能最佳。

简介：利用水平连铸生产设备进行了稀土镧微合金化TP2铜管工业化试验，采用电感耦合等离子体发射光谱法仪、金相显微镜、扫描电镜和能谱仪等手段，研究了样品成分、组织、缺陷及稀土镧的收得率等。结果表明：稀土镧微合金化TP2铜水平连铸管坯含镧24～30ppm，杂质元素硫被有效地去除，组织明显改善，表现为晶粒细化、靠近铸坯内壁分布的微裂纹产生几率降低；镧实际收得率为10％～15％，镧大多被氧化成浮渣聚集在铸造炉后膛；稀土镧微合金化TP2铜管坯外表面裂纹沿着轴向不连续分布，而且裂纹较大、较长、较多，裂纹径向最大深度为490μm。

简介：Improvingtheunitheatefficiency,reducingcoalconsumptionandtheemissionofCO2andmeetingtherequirementsofenvironmentalprotectionandenergyconservationisthegoaloftheboilerandthepowerindustry.Developmentsoflargecapacityandhighparameterultra-supercritical（USC）unitsarethetendencyofthepowerindustry.ThereisnodoubtthatthedevelopmentofUSCunitsisbasedonthedevelopmentofmaterials,especiallythematerialsusedforsuper-heaterandreheaterinhigh-temperatureUSCboiler.Duetothelongtimeexposuretotheharshenvironment,suchasbearingthe600℃steamoxidation,andwithstandingthecorrosivefluegasandflyasherosion,thematerialsrequirenotonlygoodhigh-temperaturestrength,butalsoagoodcorrosionresistance.Inconsiderationoftherequirementscitedabove,foreigncountrieshaddevelopedTP310HCbN（07Cr25Ni21CbN）austeniticheat-resistantsteel.However,thedomesticdemandsforthismaterialstilldependonimportandthecostishigh,sotheboilerandthepowerindustryexpectseagerlythatthesesteelscanbeproducedbydomesticmetallurgicalindustry,especiallyBaosteel,toreplacetheimportedproducts.Inordertosatisfytherequirementsofdomesticmanufacturingsuper-heaterandreheaterusedinultra-supercriticalpowerboiler,afterdevelopedT23、T91、T92、S30432highpressureboilertube,BaosteelbegantodevelopTP310HCbN（07Cr25Ni21CbN）austeniticstainlesssteeltubeinJanuaryof2007.Thisstudydescribesthecompositiondesign,themanufacturingprocessofproduct,andtheassessmentofperformanceofBaosteel’sTP310HCbN（07Cr25Ni21CbN）.ThedataindicatesthatpropertiesofBaosteel’sTP310HCbN（07Cr25Ni21CbN）conformtotheASMESA-213standardandGB5310standard,soitcansubstitutetheimportedproductsandissuitableformanufacturingpowerstationboilerofgreatcapacityandhighsteamparameters.