發布時間:2026-04-22 08:40:03 人氣:303939 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)平樂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。
zaichuliqiangfushixingliutishi,caiyongwaimifenghuoshuangduanmifengkeyizuidaxiandudijianshaofushiduimifengdeyingxiang,yinweitayugongyiliutijiechudelingjianshuliangzuishao。zheyeshizaiqiangfushitiaojianxiaxuanzemifengjiegouzuigulaodeyaolizhiyi。
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型平樂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)平樂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平樂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,jietouzhongdejiezhizaichengfennongduhePH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,平樂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。就平樂機械密封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。