發布時間:2026-04-18 01:40:40 人氣:302031 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).
fushiduimifengjiandexingnengyouhendayingxiang。youyumifengbizhujidelingjiangengxiao,jingdugenggao,suoyitongchangxuanzebizhujimifengnaifushidecailiao。duiyuyujiezhizhijiejiechudemifengjian,kecankaoxiangguanfushishoucezhongdeshujuxuanzeheshidecailiao。raner,zhexieshujukenengyu羅定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型羅定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羅定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羅定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);zaijiegoushejizhong,yingjinkenengbimianyetijijudejianxihesiqu。caiyongzichongxixunhuan,shimifengqiangneidejiezhichuyubuduangenghuanheliudongdezhuangtai,fangzhijiezhichengfendenongdubianhua;duiyuchangqitingyongdebeng,yingjishipaichujijudeyetideng。bukenengwanquanxiaochujiegoushangdechaju。suoyiyibancaiyongfanghuzhoucheng,keyizaimifengquananzhuangbuweipentunaifushicailiaolaifangzhi。
5.電化學腐蝕。事實上,羅定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。就羅定機械密封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。