鑄件的檢測主要包括尺寸檢查、外觀和表麵的目視檢查、化(hua)學(xue)成(cheng)分(fen)分(fen)析(xi)和(he)力(li)學(xue)性(xing)能(neng)試(shi)驗(yan),對(dui)於(yu)要(yao)求(qiu)比(bi)較(jiao)重(zhong)要(yao)或(huo)鑄(zhu)造(zao)工(gong)藝(yi)上(shang)容(rong)易(yi)產(chan)生(sheng)問(wen)題(ti)的(de)鑄(zhu)件(jian),還(hai)需(xu)要(yao)進(jin)行(xing)無(wu)損(sun)檢(jian)測(ce)工(gong)作(zuo),可(ke)用(yong)於(yu)球(qiu)墨(mo)鑄(zhu)鐵(tie)件(jian)質(zhi)量(liang)檢(jian)測(ce)的(de)無(wu)損(sun)檢(jian)測(ce)技(ji)術(shu)包(bao)括(kuo)液(ye)體(ti)滲(shen)透(tou)檢(jian)測(ce)、磁粉檢測、渦流檢測、射線檢測、超聲檢測及振動檢測等。
1 鑄件表麵及近表麵缺陷的檢測
1.1 液體滲透檢測
液體滲透檢測用來檢查鑄件表麵上的各種開口缺陷,如表麵裂紋、表麵針孔等肉眼難以發現的缺陷。常用的滲透檢測是著色檢測,它是將具有高滲透能力的有色(一般為紅色)液體(滲透劑)浸濕或噴灑在鑄件表麵上,滲透劑滲入到開口缺陷裏麵,快速擦去表麵滲透液層,再將易幹的顯示劑(也叫顯像劑)噴灑到鑄件表麵上,待將殘留在開口缺陷中的滲透劑吸出來後,顯示劑就被染色,從而可以反映出缺陷的形狀、大(da)小(xiao)和(he)分(fen)布(bu)情(qing)況(kuang)。需(xu)要(yao)指(zhi)出(chu)的(de)是(shi),滲(shen)透(tou)檢(jian)測(ce)的(de)精(jing)確(que)度(du)隨(sui)被(bei)檢(jian)材(cai)料(liao)表(biao)麵(mian)粗(cu)糙(cao)度(du)增(zeng)加(jia)而(er)降(jiang)低(di),即(ji)表(biao)麵(mian)越(yue)光(guang)檢(jian)測(ce)效(xiao)果(guo)越(yue)好(hao),磨(mo)床(chuang)磨(mo)光(guang)的(de)表(biao)麵(mian)檢(jian)測(ce)精(jing)確(que)度(du)高(gao),甚(shen)至(zhi)可(ke)以(yi)檢(jian)測(ce)出(chu)晶(jing)間(jian)裂(lie)紋(wen)。除(chu)著(zhe)色(se)檢(jian)測(ce)外(wai),熒(ying)光(guang)滲(shen)透(tou)檢(jian)測(ce)也(ye)是(shi)常(chang)用(yong)的(de)液(ye)體(ti)滲(shen)透(tou)檢(jian)測(ce)方(fang)法(fa),它(ta)需(xu)要(yao)配(pei)置(zhi)紫(zi)外(wai)光(guang)燈(deng)進(jin)行(xing)照(zhao)射(she)觀(guan)察(cha),檢(jian)測(ce)靈(ling)敏(min)度(du)比(bi)著(zhe)色(se)檢(jian)測(ce)高(gao)。
1.2 渦流檢測
渦流檢測適用於檢查表麵以下一般不大於6~7MM深的缺陷。渦流檢測分放置式線圈法和穿過式線圈法2種。:當試件被放在通有交變電流的線圈附近時,進入試件的交變磁場可在試件中感生出方向與激勵磁場相垂直的、呈渦流狀流動的電流(渦流),woliuhuichanshengyiyujilicichangfangxiangxiangfandecichang,shixianquanzhongdeyuancichangyoubufenjianshao,congeryinqixianquanzukangdebianhua。ruguozhujianbiaomiancunzaiquexian,zewoliudediantezhenghuifashengjibian,congerjiancechuquexiandecunzai,woliujiancedezhuyaoquedianshibunengzhiguanxianshitancechudequexiandaxiaohexingzhuang,yibanzhinengquedingchuquexiansuozaibiaomianweizhiheshendu,lingwaitaduigongjianbiaomianshangxiaodekaikouquexiandejianchulingminduburushentoujiance。
1.3 磁粉檢測
磁粉檢測適合於檢測表麵缺陷及表麵以下數毫米深的缺陷,它需要直流(或交流)磁化設備和磁粉(或磁懸浮液)cainengjinxingjiancecaozuo。cihuashebeiyonglaizaizhujianneiwaibiaomianchanshengcichang,cifenhuocixuanfuyeyonglaixianshiquexian。dangzaizhujianyidingfanweineichanshengcichangshi,cihuaquyuneidequexianjiuhuichanshengloucichang,dangsashangcifenhuoxuanfuyeshi,cifenbeixizhu,zheyangjiukeyixianshichuquexianlai。zheyangxianshichudequexianjibenshangdoushihengqiecilixiandequexian,duiyupingxingyucilixiandechangtiaoxingquexianzexianshibuchulai,weici,caozuoshixuyaobuduangaibiancihuafangxiang,yibaozhengnenggoujianzhachuweizhifangxiangdegegequexian。
2 鑄件內部缺陷的檢測
對於內部缺陷,常用的無損檢測方法是射線檢測和超聲檢測。其中射線檢測效果好,它能夠得到反映內部缺陷種類、形狀、大小和分布情況的直觀圖像,但對於大厚度的大型鑄件,超聲檢測是很有效的,可以比較精確地測出內部缺陷的位置、當量大小和分布情況。
2.1 射線檢測(微焦點XRAY)
射線檢測,一般用X射線或γ射she線xian作zuo為wei射she線xian源yuan,因yin此ci需xu要yao產chan生sheng射she線xian的de設she備bei和he其qi他ta附fu屬shu設she施shi,當dang工gong件jian置zhi於yu射she線xian場chang照zhao射she時shi,射she線xian的de輻fu射she強qiang度du就jiu會hui受shou到dao鑄zhu件jian內nei部bu缺que陷xian的de影ying響xiang。穿chuan過guo鑄zhu件jian射she出chu的de輻fu射she強qiang度du隨sui著zhe缺que陷xian大da小xiao、xingzhidebutongeryoujubudebianhua,xingchengquexiandeshexiantuxiang,tongguoshexianjiaopianyuyixianxiangjilu,huozhetongguoyingguangpingyuyishishijianceguancha,huozhetongguofushejishuyijiance。qizhongtongguoshexianjiaopianxianxiangjiludefangfashichangyongdefangfa,yejiushitongchangsuoshuodeshexianzhaoxiangjiance,shexianzhaoxiangsuofanyingchulaidequexiantuxiangshizhiguande,quexianxingzhuang、大小、數量、平ping麵mian位wei置zhi和he分fen布bu範fan圍wei都dou能neng呈cheng現xian出chu來lai,隻zhi是shi缺que陷xian深shen度du一yi般ban不bu能neng反fan映ying出chu來lai,需xu要yao采cai取qu特te殊shu措cuo施shi和he計ji算suan才cai能neng確que定ding。現xian在zai出chu現xian應ying用yong射she線xian計ji算suan機ji層ceng析xi照zhao相xiang方fang法fa,由you於yu設she備bei比bi較jiao昂ang貴gui,使shi用yong成cheng本ben高gao,目mu前qian還hai無wu法fa普pu及ji,但dan這zhe種zhong新xin技ji術shu代dai表biao了le高gao清qing晰xi度du射she線xian檢jian測ce技ji術shu未wei來lai發fa展zhan的de方fang向xiang。此ci外wai,使shi用yong近jin似si點dian源yuan的de微wei焦jiao點dianX射(she)線(xian)係(xi)統(tong)實(shi)際(ji)上(shang)也(ye)可(ke)消(xiao)除(chu)較(jiao)大(da)焦(jiao)點(dian)設(she)備(bei)產(chan)生(sheng)的(de)模(mo)糊(hu)邊(bian)緣(yuan),使(shi)圖(tu)像(xiang)輪(lun)廓(kuo)清(qing)晰(xi)。使(shi)用(yong)數(shu)字(zi)圖(tu)像(xiang)係(xi)統(tong)可(ke)提(ti)高(gao)圖(tu)像(xiang)的(de)信(xin)噪(zao)比(bi),進(jin)一(yi)步(bu)提(ti)高(gao)圖(tu)像(xiang)清(qing)晰(xi)度(du)。
2.2 超聲檢測
超chao聲sheng檢jian測ce也ye可ke用yong於yu檢jian查zha內nei部bu缺que陷xian,它ta是shi利li用yong具ju有you高gao頻pin聲sheng能neng的de聲sheng束shu在zai鑄zhu件jian內nei部bu的de傳chuan播bo中zhong,碰peng到dao內nei部bu表biao麵mian或huo缺que陷xian時shi產chan生sheng反fan射she而er發fa現xian缺que陷xian。反fan射she聲sheng能neng的de大da小xiao是shi內nei表biao麵mian或huo缺que陷xian的de指zhi向xiang性xing和he性xing質zhi以yi及ji這zhe種zhong反fan射she體ti的de聲sheng阻zu抗kang的de函han數shu,因yin此ci可ke以yi應ying用yong各ge種zhong缺que陷xian或huo內nei表biao麵mian反fan射she的de聲sheng能neng來lai檢jian測ce缺que陷xian的de存cun在zai位wei置zhi、壁厚或者表麵下缺陷的深度。超聲檢測作為一種應用比較廣泛的無損檢測手段,其主要優勢表現在:檢測靈敏度高,可以探測細小的裂紋;具有大的穿透能力,可以探測厚截麵鑄件。其主要局限性在於:對於輪廓尺寸複雜和指向性不好的斷開性缺陷的反射波形解釋困難;對於不合意的內部結構,例如晶粒大小、組織結構、多孔性、夾雜含量或細小的分散析出物等,同樣妨礙波形解釋;另外,檢測時需要參考標準試塊。[
鑄件缺陷如何修補
鑄件:解決鑄件縮鬆缺陷的方法,根本的著眼點就是“熱平衡”。其方法是:(1)在zai機ji床chuang鑄zhu件jian結jie構gou形xing成cheng的de厚hou處chu與yu熱re節jie處chu,實shi行xing快kuai速su凝ning固gu,人ren為wei地di造zao成cheng機ji床chuang鑄zhu件jian各ge處chu溫wen度du場chang的de基ji本ben平ping衡heng。采cai用yong內nei外wai冷leng鐵tie,局ju部bu采cai用yong蓄xu熱re量liang大da的de鋯gao英ying砂sha,鉻ge鐵tie礦kuang砂sha或huo特te種zhong塗tu料liao。(2)helidegongyisheji。neijiaodaoshezaijichuangzhujianxiangduipubichu,shushiduoqiefensan。shizaojinruhoubichudejinshuyelvxianninggu,bobichuhouninggu,shigechujibendadaojunhengninggu。duiyubihoujunyundejichuangzhujian,caiyongduogeneijiaodaohechuqikong。neijiaodaoduo,fensanyujunbu,shizhengtireliangjunheng。chuqikongxiqieduo,jipaiqitongchangyouqisanrezuoyong。(3)改變內澆道的位置(4)選用蓄熱量大的造型材料,這對用消失模生產抗磨產品極為重要!鉻鐵礦砂取代石英砂等蓄熱量小的其它砂種,會取得良好的效果,澆畢微震更優!(5)低溫快燒,開放式澆注係統。使金屬液快速,平穩,均衡地充滿鑄型。這要因件製宜。(6)球鐵的機床鑄型強度大,表麵硬度≧90,砂箱剛性大,對消除縮鬆有利。(7)需要冒口時,當首遷熱冒口,且離開熱節。若將冒口置於熱節上,必將加大冒口尺寸,形成“熱上加熱”。弄不好,非但縮鬆難除,還會產生集中性縮孔,又降低了工藝出品率。(8)鑄型傾斜擺放與合金化,都獲益。消除機床鑄件縮鬆缺陷是一個複雜的認識與實施過程。應以“熱平衡”為wei基ji本ben原yuan則ze,對dui雎ju體ti鑄zhu件jian做zuo科ke學xue分fen析xi,製zhi訂ding合he理li的de工gong藝yi方fang案an,遷qian擇ze好hao適shi宜yi的de造zao型xing材cai料liao,工gong裝zhuang及ji正zheng確que操cao作zuo且qie標biao準zhun化hua。那na麼me任ren何he機ji床chuang鑄zhu件jian的de縮suo鬆song缺que陷xian都dou可ke以yi解jie決jue。
由於多種因素影響,常常會出現氣孔、針孔、夾渣、裂紋、凹坑等缺陷。常用的修補設備為氬弧焊機、電阻焊機、冷焊機等。對於質量與外觀要求不高的鑄件缺陷可以用氬弧焊機等發熱量大、速度快的焊機來修補。但在精密鑄件缺陷修補領域,由於氬焊熱影響大,修補時會造成鑄件變形、硬度降低、砂眼、局部退火、開裂、針孔、磨損、劃傷、咬邊、或huo者zhe是shi結jie合he力li不bu夠gou及ji內nei應ying力li損sun傷shang等deng二er次ci缺que陷xian。冷leng焊han機ji正zheng好hao克ke服fu了le以yi上shang缺que點dian,其qi優you點dian主zhu要yao表biao現xian在zai熱re影ying響xiang區qu域yu小xiao,鑄zhu件jian無wu需xu預yu熱re,常chang溫wen冷leng焊han修xiu補bu,因yin而er無wu變bian形xing、咬邊和殘餘應力,不會產生局部退火,不改變鑄件的金屬組織狀態。因而冷焊機適用於精密鑄件的表麵缺陷修補。冷焊的焊補範圍為Φ1.5-Φ1.2mmhanbudianfanfuronghuaduijideguocheng,zaidamianjiquexianxiubuguochengzhong,xiufuxiaolvshizhiyueqiguangfantuiguangyingyongdeweiyiyinsu。duiyudaquexian,tuijianchuantonghanbugongyiyuzhuzaoquexianxiubujidefuheyingyong。keyoushiwomendequexianmeiyouhenduo,jiububiyaotourujiaodadechengben,womenyongyixiexiubujijiukeyixiubuhaode,fangbianjiandan,lirutiezhicailiaode,womenkeyiyong(勁素成)JS902修xiu補bu一yi下xia就jiu可ke以yi了le,用yong不bu完wan可ke以yi放fang到dao以yi後hou再zai用yong,這zhe樣yang可ke以yi為wei我wo們men的de廠chang家jia節jie省sheng成cheng本ben啊a,讓rang我wo們men的de鑄zhu造zao廠chang家jia把ba更geng多duo的de資zi金jin投tou入ru到dao提ti高gao產chan品pin本ben身shen質zhi量liang上shang,讓rang使shi用yong者zhe創chuang造zao更geng多duo的de財cai富fu。