白銀機械密封的腐蝕類型

　　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).
　　fushiduimifengjiandexingnengyouhendayingxiang。youyumifengbizhujidelingjiangengxiao，jingdugenggao
，suoyitongchangxuanzebizhujimifengnaifushidecailiao。duiyuyujiezhizhijiejiechudemifengjian
，kecankaoxiangguanfushishoucezhongdeshujuxuanzeheshidecailiao。raner，zhexieshujukenengyu白銀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
、tonghejindeng。rongyichanshengyinglifushi。zaiyinglifushiguochengzhong，yibanzaijinshubiaomianxingchengxuanzexingfushicao，ranhoujixujubufushi，zuihouzaiyinglizuoyongxiacongcaodichanshengliewen。dianxingdelizishi104型白銀機械密封的傳動套筒，由1Cr18Ni9Ti製(zhi)成(cheng)。在(zai)氨(an)水(shui)泵(beng)中(zhong)使(shi)用(yong)時(shi)，傳(chuan)動(dong)套(tao)筒(tong)的(de)傳(chuan)動(dong)耳(er)環(huan)最(zui)容(rong)易(yi)產(chan)生(sheng)應(ying)力(li)腐(fu)蝕(shi)裂(lie)紋(wen)
，從(cong)而(er)損(sun)壞(huai)耳(er)環(huan)。所(suo)以(yi)把(ba)凹(ao)耳(er)釘(ding)換(huan)成(cheng)實(shi)心(xin)耳(er)片(pian)可(ke)以(yi)防(fang)止(zhi)這(zhe)種(zhong)應(ying)力(li)腐(fu)蝕(shi)。
　　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白銀機械密封的非主要部件造成的損壞，如彈簧座、推環、huanzuodeng。bingbunengxunsufanyingmifengxingnengdebianhua
，danqueshimocafushixiaodezhuyaoxingshizhiyi。yinci，zaiqiangtidefushijiezhizhong，mocafuyingyounaifushixinghaodecailiaozhicheng。liru
，shiyong99.5%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白銀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)jiushidianxingdelizi。yuanyinshijietouneidejiezhichuyutingzhizhuangtai，shidecanyufushifanyingdewuzhinanyijiarujietounei，jietouneidefushichanwunanyixiangwaikuosan。suizhefushidejinxing

，jietouzhongdejiezhizaichengfennongduhePHzhishangyuzhenggejiezhiyuelaiyuebutong


，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
，白銀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。就白銀機械密封摩(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。