發布時間:2026-04-22 12:37:01 人氣:304016 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1Cr18Ni9Tibuxiugangzhichengdeduodanhuang,zaixiliusuanzhongshiyonghuichuxianzhezhongqingkuang。jubufushikeyijiandanditongguolingjianshangdefushidianhekonglaishibie。jubufushishiduoxianghejinzhongdemouyixianghuodanxianggurongtizhongdemouyiyuansubeijiezhixuanzexingrongjiedefushixingshi。rugujiyingzhihejinzaigaowenqiangjiantiaojianxiashiyong,zhanjiexiangjinshugurongyibeifushi,yingzhixiangtanhuawugujiashiquqiangdu,zaijixielidezuoyongxiadaozhijingliboluo。zuoweilingyigelizi,youyuyouliguidefushi,fanyingshaojietanhuaguidebiaomianxianshimadian(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)富民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型富民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富民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)富民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hePHzhishangyuzhenggejiezhiyuelaiyuebutong,daozhijietouzhongjinshubiaomiandefushijiaju。jianxifushiduimifengxingnengfeichangyouhai。mifengquanyushuangzhouzhijiandeaocaohuidaozhibuchanghuanwufazhouxiangweiyi,shiqusuidongxing,daozhiduanmianfenlihexielou。jianxifushitongchangkeyitongguoshidangdecailiaoxuanzehehelidejiegoushejilaihuanjie。biruxuanzekangjianxifushixingnenghaodecailiao;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,富民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。就富民機械密封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。