通海口鎮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通海口鎮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型通海口鎮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通海口鎮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(yong)99.5%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通海口鎮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)；duiyuchangqitingyongdebeng
，yingjishipaichujijudeyetideng。bukenengwanquanxiaochujiegoushangdechaju。suoyiyibancaiyongfanghuzhoucheng
，keyizaimifengquananzhuangbuweipentunaifushicailiaolaifangzhi。
　　5.電化學腐蝕。事實上
，通海口鎮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。就通海口鎮機械密封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。