發布時間:2026-04-14 21:24:00 人氣:300202 來源:川工密封
1.整體腐蝕和局部腐蝕。綜合腐蝕,即與介質接觸的零件表麵發生均勻腐蝕,其特點是零件重量減輕,甚至完全腐蝕;失去力量;降低硬度。如1Cr18Ni9Ti不(bu)鏽(xiu)鋼(gang)製(zhi)成(cheng)的(de)多(duo)彈(dan)簧(huang),在(zai)稀(xi)硫(liu)酸(suan)中(zhong)使(shi)用(yong)會(hui)出(chu)現(xian)這(zhe)種(zhong)情(qing)況(kuang)。局(ju)部(bu)腐(fu)蝕(shi)可(ke)以(yi)簡(jian)單(dan)地(di)通(tong)過(guo)零(ling)件(jian)上(shang)的(de)腐(fu)蝕(shi)點(dian)和(he)孔(kong)來(lai)識(shi)別(bie)。局(ju)部(bu)腐(fu)蝕(shi)是(shi)多(duo)相(xiang)合(he)金(jin)中(zhong)的(de)某(mou)一(yi)相(xiang)或(huo)單(dan)相(xiang)固(gu)溶(rong)體(ti)中(zhong)的(de)某(mou)一(yi)元(yuan)素(su)被(bei)介(jie)質(zhi)選(xuan)擇(ze)性(xing)溶(rong)解(jie)的(de)腐(fu)蝕(shi)形(xing)式(shi)。如(ru)鈷(gu)基(ji)硬(ying)質(zhi)合(he)金(jin)在(zai)高(gao)溫(wen)強(qiang)堿(jian)條(tiao)件(jian)下(xia)使(shi)用(yong),粘(zhan)結(jie)相(xiang)金(jin)屬(shu)鈷(gu)容(rong)易(yi)被(bei)腐(fu)蝕(shi),硬(ying)質(zhi)相(xiang)碳(tan)化(hua)鎢(wu)骨(gu)架(jia)失(shi)去(qu)強(qiang)度(du),在(zai)機(ji)械(xie)力(li)的(de)作(zuo)用(yong)下(xia)導(dao)致(zhi)晶(jing)粒(li)剝(bo)落(luo)。作(zuo)為(wei)另(ling)一(yi)個(ge)例(li)子(zi),由(you)於(yu)遊(you)離(li)矽(gui)的(de)腐(fu)蝕(shi),反(fan)應(ying)燒(shao)結(jie)碳(tan)化(hua)矽(gui)的(de)表(biao)麵(mian)顯(xian)示(shi)麻(ma)點(dian)(PH>10時).
fushiduimifengjiandexingnengyouhendayingxiang。youyumifengbizhujidelingjiangengxiao,jingdugenggao,suoyitongchangxuanzebizhujimifengnaifushidecailiao。duiyuyujiezhizhijiejiechudemifengjian,kecankaoxiangguanfushishoucezhongdeshujuxuanzeheshidecailiao。raner,zhexieshujukenengyu左貢機械密封係統中使用的條件不一致,因為它們大多是靜態條件下的腐蝕數據,並且工藝流程中的介質包含雜質或二次化合物。經驗表明,壓力、溫度和滑動速度都會加速腐蝕。隨著溫度的升高,密封件的腐蝕速率呈指數增長。
在zai處chu理li強qiang腐fu蝕shi性xing流liu體ti時shi,采cai用yong外wai密mi封feng或huo雙shuang端duan密mi封feng可ke以yi最zui大da限xian度du地di減jian少shao腐fu蝕shi對dui密mi封feng的de影ying響xiang,因yin為wei它ta與yu工gong藝yi流liu體ti接jie觸chu的de零ling件jian數shu量liang最zui少shao。這zhe也ye是shi在zai強qiang腐fu蝕shi條tiao件jian下xia選xuan擇ze密mi封feng結jie構gou最zui古gu老lao的de窯yao理li之zhi一yi。
2.應力腐蝕。應力腐蝕是金屬材料在應力作用下在腐蝕環境中的腐蝕現象。無論是外載荷還是殘餘應力,都會加劇腐蝕。奧氏體不鏽鋼、銅(tong)合(he)金(jin)等(deng)。容(rong)易(yi)產(chan)生(sheng)應(ying)力(li)腐(fu)蝕(shi)。在(zai)應(ying)力(li)腐(fu)蝕(shi)過(guo)程(cheng)中(zhong),一(yi)般(ban)在(zai)金(jin)屬(shu)表(biao)麵(mian)形(xing)成(cheng)選(xuan)擇(ze)性(xing)腐(fu)蝕(shi)槽(cao),然(ran)後(hou)繼(ji)續(xu)局(ju)部(bu)腐(fu)蝕(shi),最(zui)後(hou)在(zai)應(ying)力(li)作(zuo)用(yong)下(xia)從(cong)槽(cao)底(di)產(chan)生(sheng)裂(lie)紋(wen)。典(dian)型(xing)的(de)例(li)子(zi)是(shi)104型左貢機械密封的傳動套筒,由1Cr18Ni9Tizhicheng。zaianshuibengzhongshiyongshi,chuandongtaotongdechuandongerhuanzuirongyichanshengyinglifushiliewen,congersunhuaierhuan。suoyibaaoerdinghuanchengshixinerpiankeyifangzhizhezhongyinglifushi。
3.介(jie)質(zhi)腐(fu)蝕(shi)。密(mi)封(feng)件(jian)和(he)流(liu)體(ti)之(zhi)間(jian)的(de)高(gao)速(su)運(yun)動(dong)導(dao)致(zhi)接(jie)觸(chu)表(biao)麵(mian)上(shang)的(de)微(wei)小(xiao)不(bu)均(jun)勻(yun)。當(dang)流(liu)體(ti)為(wei)腐(fu)蝕(shi)性(xing)介(jie)質(zhi)時(shi),會(hui)加(jia)速(su)密(mi)封(feng)接(jie)觸(chu)麵(mian)的(de)化(hua)學(xue)反(fan)應(ying),有(you)時(shi)有(you)益(yi),有(you)時(shi)有(you)害(hai)。如(ru)果(guo)形(xing)成(cheng)的(de)氧(yang)化(hua)層(ceng)被(bei)破(po)壞(huai),就(jiu)會(hui)發(fa)生(sheng)腐(fu)蝕(shi)。磨(mo)損(sun)和(he)磨(mo)蝕(shi)交(jiao)替(ti)作(zuo)用(yong)對(dui)材(cai)料(liao)造(zao)成(cheng)的(de)損(sun)傷(shang)稱(cheng)為(wei)磨(mo)蝕(shi)。通(tong)常(chang),磨(mo)損(sun)對(dui)左貢機械密封的非主要部件造成的損壞,如彈簧座、推環、環huan座zuo等deng。並bing不bu能neng迅xun速su反fan映ying密mi封feng性xing能neng的de變bian化hua,但dan卻que是shi摩mo擦ca副fu失shi效xiao的de主zhu要yao形xing式shi之zhi一yi。因yin此ci,在zai腔qiang體ti的de腐fu蝕shi介jie質zhi中zhong,摩mo擦ca副fu應ying由you耐nai腐fu蝕shi性xing好hao的de材cai料liao製zhi成cheng。例li如ru,使shi用yong99.5%高純度氧化鋁陶瓷或不含遊離矽的熱壓燒結碳化矽。
4.間(jian)隙(xi)腐(fu)蝕(shi)。當(dang)介(jie)質(zhi)處(chu)於(yu)金(jin)屬(shu)與(yu)金(jin)屬(shu)或(huo)非(fei)金(jin)屬(shu)構(gou)件(jian)之(zhi)間(jian),且(qie)存(cun)在(zai)小(xiao)間(jian)隙(xi)時(shi),由(you)於(yu)介(jie)質(zhi)處(chu)於(yu)停(ting)滯(zhi)狀(zhuang)態(tai),間(jian)隙(xi)內(nei)金(jin)屬(shu)的(de)腐(fu)蝕(shi)會(hui)加(jia)速(su),這(zhe)種(zhong)現(xian)象(xiang)稱(cheng)為(wei)間(jian)隙(xi)腐(fu)蝕(shi)。例(li)如(ru)左貢機械密封彈簧座與軸之間的溝槽或衝蝕點,補償環輔助密封環與軸之間的溝槽或衝蝕點(這裏當然有微動磨損)就jiu是shi典dian型xing的de例li子zi。原yuan因yin是shi接jie頭tou內nei的de介jie質zhi處chu於yu停ting滯zhi狀zhuang態tai,使shi得de參can與yu腐fu蝕shi反fan應ying的de物wu質zhi難nan以yi加jia入ru接jie頭tou內nei,接jie頭tou內nei的de腐fu蝕shi產chan物wu難nan以yi向xiang外wai擴kuo散san。隨sui著zhe腐fu蝕shi的de進jin行xing,接jie頭tou中zhong的de介jie質zhi在zai成cheng分fen濃nong度du和hePH值zhi上shang與yu整zheng個ge介jie質zhi越yue來lai越yue不bu同tong,導dao致zhi接jie頭tou中zhong金jin屬shu表biao麵mian的de腐fu蝕shi加jia劇ju。間jian隙xi腐fu蝕shi對dui密mi封feng性xing能neng非fei常chang有you害hai。密mi封feng圈quan與yu雙shuang軸zhou之zhi間jian的de凹ao槽cao會hui導dao致zhi補bu償chang環huan無wu法fa軸zhou向xiang位wei移yi,失shi去qu隨sui動dong性xing,導dao致zhi端duan麵mian分fen離li和he泄xie漏lou。間jian隙xi腐fu蝕shi通tong常chang可ke以yi通tong過guo適shi當dang的de材cai料liao選xuan擇ze和he合he理li的de結jie構gou設she計ji來lai緩huan解jie。比bi如ru選xuan擇ze抗kang間jian隙xi腐fu蝕shi性xing能neng好hao的de材cai料liao;在zai結jie構gou設she計ji中zhong,應ying盡jin可ke能neng避bi免mian液ye體ti積ji聚ju的de間jian隙xi和he死si區qu。采cai用yong自zi衝chong洗xi循xun環huan,使shi密mi封feng腔qiang內nei的de介jie質zhi處chu於yu不bu斷duan更geng換huan和he流liu動dong的de狀zhuang態tai,防fang止zhi介jie質zhi成cheng分fen的de濃nong度du變bian化hua;duiyuchangqitingyongdebeng,yingjishipaichujijudeyetideng。bukenengwanquanxiaochujiegoushangdechaju。suoyiyibancaiyongfanghuzhoucheng,keyizaimifengquananzhuangbuweipentunaifushicailiaolaifangzhi。
5.電化學腐蝕。事實上,左貢機械密封的各種腐蝕形式或多或少都與銅的電化學腐蝕有關。就左貢機械密封mocafueryan,tamenjingchangshoudaodianhuaxuefushidesunhai,yinweimocafuzhongtongchangshiyongbutongdecailiao。dangtamenchuyudianjiezhirongyezhongshi,butongcailiaojiechushihuichuxiandianouhexiaoying,jiyizhongcailiaodefushidedaocujin,lingyizhongcailiaodefushidedaoyizhi。liru,dangtongheniegegangyongyuyanghuajiezhishi,niegegangbeidianlihefenjie。yanshui、海水、稀鹽酸、稀硫酸等。都是典型的電解質溶液,密封件容易發生電化學腐蝕。所以最好選擇材料或者電位相近的陶瓷,以及玻璃纖維填充的PTFE。