發布時間:2026-04-14 21:21:09 人氣:300194 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).
腐fu蝕shi對dui密mi封feng件jian的de性xing能neng有you很hen大da影ying響xiang。由you於yu密mi封feng比bi主zhu機ji的de零ling件jian更geng小xiao,精jing度du更geng高gao,所suo以yi通tong常chang選xuan擇ze比bi主zhu機ji密mi封feng耐nai腐fu蝕shi的de材cai料liao。對dui於yu與yu介jie質zhi直zhi接jie接jie觸chu的de密mi封feng件jian,可ke參can考kao相xiang關guan腐fu蝕shi手shou冊ce中zhong的de數shu據ju選xuan擇ze合he適shi的de材cai料liao。然ran而er,這zhe些xie數shu據ju可ke能neng與yu婁煩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型婁煩機械密封的傳動套筒,由1Cr18Ni9Tizhicheng。zaianshuibengzhongshiyongshi,chuandongtaotongdechuandongerhuanzuirongyichanshengyinglifushiliewen,congersunhuaierhuan。suoyibaaoerdinghuanchengshixinerpiankeyifangzhizhezhongyinglifushi。
3.jiezhifushi。mifengjianheliutizhijiandegaosuyundongdaozhijiechubiaomianshangdeweixiaobujunyun。dangliutiweifushixingjiezhishi,huijiasumifengjiechumiandehuaxuefanying,youshiyouyi,youshiyouhai。ruguoxingchengdeyanghuacengbeipohuai,jiuhuifashengfushi。mosunhemoshijiaotizuoyongduicailiaozaochengdesunshangchengweimoshi。tongchang,mosundui婁煩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.jianxifushi。dangjiezhichuyujinshuyujinshuhuofeijinshugoujianzhijian,qiecunzaixiaojianxishi,youyujiezhichuyutingzhizhuangtai,jianxineijinshudefushihuijiasu,zhezhongxianxiangchengweijianxifushi。liru婁煩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(he)PH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);對dui於yu長chang期qi停ting用yong的de泵beng,應ying及ji時shi排pai出chu積ji聚ju的de液ye體ti等deng。不bu可ke能neng完wan全quan消xiao除chu結jie構gou上shang的de差cha距ju。所suo以yi一yi般ban采cai用yong防fang護hu軸zhou承cheng,可ke以yi在zai密mi封feng圈quan安an裝zhuang部bu位wei噴pen塗tu耐nai腐fu蝕shi材cai料liao來lai防fang止zhi。
5.電化學腐蝕。事實上,婁煩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。就婁煩機械密封摩(mo)擦(ca)副(fu)而(er)言(yan),它(ta)們(men)經(jing)常(chang)受(shou)到(dao)電(dian)化(hua)學(xue)腐(fu)蝕(shi)的(de)損(sun)害(hai),因(yin)為(wei)摩(mo)擦(ca)副(fu)中(zhong)通(tong)常(chang)使(shi)用(yong)不(bu)同(tong)的(de)材(cai)料(liao)。當(dang)它(ta)們(men)處(chu)於(yu)電(dian)解(jie)質(zhi)溶(rong)液(ye)中(zhong)時(shi),不(bu)同(tong)材(cai)料(liao)接(jie)觸(chu)時(shi)會(hui)出(chu)現(xian)點(dian)耦(ou)合(he)效(xiao)應(ying),即(ji)一(yi)種(zhong)材(cai)料(liao)的(de)腐(fu)蝕(shi)得(de)到(dao)促(cu)進(jin),另(ling)一(yi)種(zhong)材(cai)料(liao)的(de)腐(fu)蝕(shi)得(de)到(dao)抑(yi)製(zhi)。例(li)如(ru),當(dang)銅(tong)和(he)鎳(nie)鉻(ge)鋼(gang)用(yong)於(yu)氧(yang)化(hua)介(jie)質(zhi)時(shi),鎳(nie)鎘(ge)鋼(gang)被(bei)電(dian)離(li)和(he)分(fen)解(jie)。鹽(yan)水(shui)、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。