邢台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).
　　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邢台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shi104型邢台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邢台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邢台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)PHzhishangyuzhenggejiezhiyuelaiyuebutong，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，邢台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。就邢台機械密封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。