简介:我公司是由年产5000t合成氨发展到现在年产30万t合成氨、52万t尿素、5万t甲醇的大型化肥企业。生产能力虽然大幅度的提高,但还是固定床间歇工艺,工艺落后,单套生产能力低,物耗、能耗和产品成本高,在一定程度上制约企业的经济效益和社会效益。特别是我国加入WTO后,关贸市场的开放,国内化肥市场的竞争日益加剧,企业要发展要生存,必须开拓创新,进行技术改造。为了进一步降低戒本,提高经济效益,公司决定对二分厂进行改造,采用杭州林达公司的等高压双甲技术,三大内件由林达提供、自己安装、取代铜洗的l套双甲新工艺,一次开车成功,现己运行正常,经济效益显著提高,该技术对中、小化肥企业的发展和生存有着现实重要意义值得推广应用。
简介:对南钢生产的40mm厚800MPa级N800CF高强度水电钢进行了冷裂纹敏感性测试,并采用SMAW、GMAW和SAW三种方法对N800CF钢进行了焊接工艺评定。结果表明。南钢生产的N800CF水电钢预热80℃时可避免冷裂纹的产生,焊接接头综合性能良好。
简介:Threedifferenttypesoftensilestrength(TS)980MPagradeadvancedhigh-strengthsteelsusedinautomotiveapplications,namely,980MS(martensitesteel),980DP(dualphase)and980QP(quenchingandpartitioning)steelswereexamined.ThedelayedfractureresistanceofthesteelswasevaluatedusingaU-bendtest,slowstrainratetest(SSRT)andaconstantloadtensiletest.Theresultsindicatedthatallthesteelscouldpassthe300hHClsolutionimmersiontestandnoneoftheU-bendspecimenswasfracturedinthetest.However,thesteelsexhibiteddifferentsusceptibilitiestodelayedfractureunderSSRTandtheconstantloadtensiletests.980DPexhibitedthehighestresistancetodelayedfractureamongallthesamples,while980MSwasfoundtobethemostsusceptibletodelayedfracture.
简介:ThemicrostructureandhardnessoftheHAZina800MPagradeultra-low-carbonmicroalloyedsteelwerestudied.Theresultsindicatethattheheataffectedzone(HAZ)oftheRPC(Relaxation-Precipitation-Controlling)steelpossessesacontinuousgradientstructure,andcanbeclassifiedintothreezones,i.e.CGHAZ(coarse-grainHAZ),FGHAZ(fine-grainHAZ)andICHAZ(intercriticaltemperatureHAZ).ThemicrostructuresintheHAZareallcomposedofbainite-likestructure.ThemicrostructareintheCGHAZmainlyconsistsoflath-likebainiteandgranularbainite.Theinfluencesofheatinputandt8/5onthehardnessintheHAZofRPCsteelarenotable.Withtheincreaseofheatinputandt8/5,thesofteningtendencyofHAZbecomesobvious.ThehardeningphenomenonthatnormallyoccursintheCGHAZdoesnottakeplacewiththissteelintherangeofexperimentalconditions.ThesofteningintheICHAZisboundtooccur.Henceappropriateweldingtechnologiesneedtobeselected.