管道(鋼管)在不同的工作環境中使用,為減緩或防止管道在外介質的化學、電化學作用下或由微生物的代謝活動而被侵蝕和變質在其外壁上塗2層或3層聚乙烯(3PE)以達到管道防腐,3pe防腐管使用壽命延長3-5倍。(1)通過對歐洲聚乙烯防腐層30年(nian)應(ying)用(yong)史(shi)的(de)回(hui)顧(gu),雖(sui)然(ran)理(li)論(lun)上(shang)剝(bo)離(li)防(fang)腐(fu)層(ceng)下(xia)會(hui)發(fa)生(sheng)腐(fu)蝕(shi)或(huo)應(ying)力(li)腐(fu)蝕(shi)開(kai)裂(lie),但(dan)目(mu)前(qian)還(hai)沒(mei)有(you)發(fa)生(sheng)剝(bo)離(li)防(fang)腐(fu)層(ceng)下(xia)出(chu)現(xian)膜(mo)下(xia)腐(fu)蝕(shi)或(huo)應(ying)力(li)開(kai)裂(lie)的(de)案(an)例(li)。在(zai)德(de)國(guo)曼(man)內(nei)斯(si)曼(man)研(yan)究(jiu)所(suo),曾(zeng)經(jing)進(jin)行(xing)了(le)長(chang)期(qi)的(de)腐(fu)蝕(shi)實(shi)驗(yan)室(shi)實(shi)驗(yan),以(yi)模(mo)擬(ni)防(fang)腐(fu)層(ceng)應(ying)用(yong)效(xiao)果(guo)。腐(fu)蝕(shi)實(shi)驗(yan)環(huan)境(jing)有(you)土(tu)壤(rang)、水、試驗主要檢查應力腐蝕開裂問題,其實驗防腐是把有缺陷的聚乙烯防腐層鋼管置於腐蝕條件和應力條件下,腐蝕環境為含有NaHCO3的沙土環境,溫度70℃,管地電位-430~-460mV,gangguanbiaomianyibutongfangshiyuchuli,suoyougangguanjundaiyaxunhuan。shiyanjieshu,fangfucengquexianzhouweihuoduohuoshaodouyouboli,danboliquweifaxianfushi。biaomianwuyangqihuapidegangguanweichuxianyinglikailie,youyanghuapidegangguanchuxianlekailie,liewenzuidashendu0.2mm,可能是由應力腐蝕造成。由此得出結論,徹底的表麵處理是防止應力開裂的有效手段。

(2)目前國內外防腐層應用效果評價很好,對其使用中產生的缺陷報道的很少。報道的主要缺點有露點、剝離、陰極剝離、陰極保護屏蔽、剝(bo)離(li)防(fang)腐(fu)層(ceng)膜(mo)下(xia)腐(fu)蝕(shi)等(deng),而(er)且(qie)大(da)部(bu)分(fen)有(you)關(guan)缺(que)陷(xian)的(de)報(bao)道(dao)還(hai)停(ting)留(liu)在(zai)理(li)論(lun)推(tui)測(ce)階(jie)段(duan),如(ru)資(zi)料(liao)中(zhong)提(ti)到(dao)陰(yin)極(ji)保(bao)護(hu)屏(ping)蔽(bi)的(de)問(wen)題(ti),到(dao)目(mu)前(qian)還(hai)沒(mei)有(you)關(guan)於(yu)防(fang)腐(fu)層(ceng)實(shi)際(ji)運(yun)作(zuo)中(zhong)出(chu)現(xian)陰(yin)極(ji)保(bao)護(hu)屏(ping)蔽(bi)的(de)實(shi)例(li)報(bao)道(dao)。經(jing)過(guo)多(duo)年(nian)的(de)實(shi)踐(jian)表(biao)明(ming),隨(sui)著(zhe)使(shi)用(yong)年(nian)限(xian)的(de)增(zeng)加(jia),出(chu)現(xian)缺(que)陷(xian)最(zui)少(shao)的(de)塗(tu)層(ceng)係(xi)統(tong)是(shi)FBE/擠壓聚乙烯3層結構防腐係統。
3PE防腐鋼管防腐結構為:聚乙烯三層結構防護層又稱三層pe/pp。是近幾年從引進的先進的外防腐技術。其結構由以下三層組成:底層為熔結環氧,中間層為膠粘劑,麵層為擠塑聚乙烯。三層pe防fang腐fu層ceng,將jiang環huan氧yang塗tu層ceng的de界jie麵mian特te性xing和he耐nai化hua學xue特te性xing,與yu擠ji壓ya聚ju乙yi烯xi防fang腐fu層ceng的de機ji械xie保bao護hu特te性xing等deng優you點dian結jie合he起qi來lai,從cong而er顯xian著zhe改gai善shan了le各ge自zi的de性xing能neng。據ju有you關guan資zi料liao介jie紹shao,三san層cengpe可使埋地管道的壽命達到50年(nian)。該(gai)防(fang)腐(fu)塗(tu)層(ceng)在(zai)油(you)氣(qi)長(chang)輸(shu)管(guan)道(dao)中(zhong)應(ying)用(yong)廣(guang)泛(fan)。熔(rong)結(jie)環(huan)氧(yang)粉(fen)末(mo)是(shi)采(cai)用(yong)熱(re)固(gu)性(xing)粉(fen)末(mo)塗(tu)料(liao)噴(pen)塗(tu)一(yi)次(ci)成(cheng)膜(mo)的(de)生(sheng)產(chan)工(gong)藝(yi),其(qi)防(fang)腐(fu)性(xing)能(neng)極(ji)其(qi)優(you)越(yue),耐(nai)化(hua)學(xue)腐(fu)蝕(shi)性(xing)好(hao),與(yu)基(ji)材(cai)粘(zhan)結(jie)強(qiang)度(du)高(gao),表(biao)麵(mian)光(guang)滑(hua),耐(nai)磨(mo)、耐高溫,壽命可超過40年;塗tu裝zhuang時shi充chong分fen熔rong化hua流liu動dong,流liu平ping覆fu蓋gai於yu鋼gang管guan表biao麵mian,與yu基ji材cai間jian沒mei有you空kong隙xi,完wan全quan緊jin密mi結jie合he,且qie在zai此ci過guo程cheng中zhong發fa生sheng化hua學xue反fan應ying,環huan氧yang粉fen末mo樹shu脂zhi受shou熱re固gu化hua交jiao聯lian形xing成cheng連lian續xu的de熱re固gu性xing聚ju合he物wu,和he鋼gang管guan形xing成cheng某mou種zhong程cheng度du的de化hua學xue鍵jian,從cong而er決jue定ding了le它ta的de優you良liang防fang腐fu層ceng起qi源yuan於yu穿chuan越yue工gong程cheng。它ta的de補bu口kou采cai用yong雙shuang組zu份fen液ye態tai環huan氧yang,一yi般ban2gexiaoshijikewanquanguhua,dadatigaoleshigongsudu。yincirongjiehuanyangfenmofangfutucengbeiguangfanyingyongyulushang,shuixia,haididengguanxiandetuzhuangfangfu,qieyouchengshudeguojiheguoneibiaozhunyuzhixiangduiying,zaimeiguogaifangfuxingshijihuqudailechuantongshangshiyongdemeijiaoyouciqi;在國內山東灣大橋dn1500(dn1600)鋼管樁就采用了三層熔結環氧粉末塗裝以抵抗海水的腐蝕。其缺點是造價較高,目前基本達到40-60元/m2。
shangzhougangcaiqixianjiagejundafushangzhang,guowuyuanjiugangtiexingyequchannenggongzuozhonggebieqiyecunzaidedingfengweifaweiguixingweizhankaitiaozha,guoneiloushiyinglaixinyiluntiaokongchao。gangtiexianhuojiaoyipingtai——西xi本ben新xin幹gan線xian發fa布bu最zui新xin研yan究jiu報bao告gao指zhi出chu,近jin期qi鋼gang鐵tie去qu產chan能neng及ji環huan保bao治zhi理li題ti材cai再zai度du升sheng溫wen發fa酵jiao,國guo內nei鋼gang材cai市shi場chang供gong應ying存cun在zai進jin一yi步bu下xia降jiang的de預yu期qi,對dui於yu當dang前qian火huo熱re的de鋼gang材cai市shi場chang或huo將jiang再zai次ci形xing成cheng助zhu推tui影ying響xiang,預yu計ji短duan期qi國guo內nei鋼gang價jia仍reng將jiang延yan續xu上shang漲zhang走zou勢shi。該gai報bao告gao數shu據ju顯xian示shi,上shang周zhou全quan國guo35個主要市場螺紋鋼庫存量為395.1萬噸,增加7.7萬噸,增幅為1.99%;線材庫存量為86.8萬噸,增加1.9萬噸,增幅為2.24%。而從全國線材、螺紋鋼、熱軋板卷、冷軋板卷、中厚板五大品種庫存總量來看,全國綜合庫存總量為855萬噸,較前一周增加6.9萬噸,增幅為0.81%。fenxishibiaoshi,quanguogangcaishichangkucunjieshuleciqianlianxuliuzhoudexiajiangqushi,zhuanerchuxianshangsheng,kucunshangshengdepinzhongzhuyaoweijianzhugangcai,bancaikucunliangyiranchengxiajiangtaishi。dangqiandongbeidiqugongdiyijibenquanmiantinggong,huabeijingjinjidiqufabudafanweihuanbaozhili,bushaogongditinggongzhengzhi,guoneigangcaishichangxuqiuquruo,kucunyoujiangzhuansheng。

