發布時間:2026-04-23 20:06:22 人氣:304652 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).
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)大田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。
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、tonghejindeng。rongyichanshengyinglifushi。zaiyinglifushiguochengzhong,yibanzaijinshubiaomianxingchengxuanzexingfushicao,ranhoujixujubufushi,zuihouzaiyinglizuoyongxiacongcaodichanshengliewen。dianxingdelizishi104型大田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大田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大田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hePH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);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,大田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。就大田鎮機械密封摩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。