通(tong)常情況下,金(jin)相(xiang)試(shi)(shi)樣(yang)的制備包括了(le)取樣(yang)、鑲嵌、標號(hao)、磨光、顯示(shi)等幾(ji)個步(bu)驟。但(dan)不是每個金(jin)相(xiang)試(shi)(shi)樣(yang)的制備都(dou)必(bi)須(xu)經歷上(shang)述步(bu)驟。如果(guo)所(suo)選(xuan)取的試(shi)(shi)樣(yang)形狀、大小合適,便于握(wo)持磨制,則(ze)不必(bi)進(jin)(jin)行鑲嵌;如果(guo)檢驗(yan)僅是材(cai)料中非金(jin)屬夾雜(za)物或鑄鐵中的石墨,則(ze)不必(bi)進(jin)(jin)行浸蝕。總(zong)之(zhi),應根據具體(ti)目的來(lai)確(que)定制樣(yang)步(bu)驟。
1. 取樣(yang)
取(qu)樣是金相試樣制備的第一道工序,若取(qu)樣不當,則達不到檢驗目的,因此(ci),所(suo)取(qu)試樣的部位、數量、磨面方向(xiang)等(deng)應嚴格按(an)照相應的標(biao)準規定執行。
取(qu)(qu)樣(yang)(yang)(yang)(yang)(yang)(yang)中還要注意三個方(fang)面(mian)的(de)(de)選擇(ze)。其一,取(qu)(qu)樣(yang)(yang)(yang)(yang)(yang)(yang)部位和磨(mo)面(mian)方(fang)向的(de)(de)選擇(ze)。取(qu)(qu)樣(yang)(yang)(yang)(yang)(yang)(yang)部位須要和檢(jian)(jian)(jian)驗(yan)(yan)目的(de)(de)要求一樣(yang)(yang)(yang)(yang)(yang)(yang),這樣(yang)(yang)(yang)(yang)(yang)(yang)才(cai)能(neng)使切(qie)取(qu)(qu)的(de)(de)試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang)具有(you)(you)(you)代表性。必要時(shi),應(ying)(ying)在檢(jian)(jian)(jian)驗(yan)(yan)報告單中添加圖文(wen)標明(ming)取(qu)(qu)樣(yang)(yang)(yang)(yang)(yang)(yang)部位、數量和磨(mo)面(mian)方(fang)向。其二,取(qu)(qu)樣(yang)(yang)(yang)(yang)(yang)(yang)方(fang)法,由于(yu)備件材料的(de)(de)形(xing)狀各異,也有(you)(you)(you)用不(bu)規則(ze)(ze)外形(xing)的(de)(de)試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang)。若(ruo)表面(mian)不(bu)規則(ze)(ze),應(ying)(ying)將棱邊倒圓,防止(zhi)在磨(mo)制(zhi)時(shi),試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang)劃破砂紙和拋光織(zhi)(zhi)物(wu),造(zao)成被(bei)織(zhi)(zhi)物(wu)掛飛(fei),造(zao)成事故。反(fan)之,檢(jian)(jian)(jian)驗(yan)(yan)表面(mian)的(de)(de)試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang),嚴禁倒角并保證磨(mo)面(mian)平整。切(qie)取(qu)(qu)試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang)時(shi)根據被(bei)檢(jian)(jian)(jian)驗(yan)(yan)材料的(de)(de)軟硬程度(du)可采取(qu)(qu)鋸、車、刨、銑、線切(qie)割等不(bu)同方(fang)法。其三,試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang)的(de)(de)熱(re)(re)處理(li)(li)(li),經(jing)取(qu)(qu)樣(yang)(yang)(yang)(yang)(yang)(yang)而(er)獲得的(de)(de)金(jin)相(xiang)試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang),有(you)(you)(you)的(de)(de)可直接進行磨(mo)制(zhi),有(you)(you)(you)的(de)(de)則(ze)(ze)需(xu)要熱(re)(re)處理(li)(li)(li)后才(cai)能(neng)進行磨(mo)制(zhi),如檢(jian)(jian)(jian)驗(yan)(yan)鋼的(de)(de)本(ben)質晶粒度(du),非金(jin)屬夾雜物(wu),碳化物(wu)不(bu)均勻度(du)等項目的(de)(de)試(shi)樣(yang)(yang)(yang)(yang)(yang)(yang),需(xu)經(jing)熱(re)(re)處理(li)(li)(li),其處理(li)(li)(li)方(fang)法按相(xiang)應(ying)(ying)標準(zhun)規定(ding)執(zhi)行。
2. 鑲嵌
當(dang)金(jin)相檢驗的材(cai)料尺寸(cun)過小或形狀不規(gui)則時,由于(yu)不便于(yu)握持,可采用鑲嵌(qian)的方(fang)法(fa),得(de)到尺寸(cun)適當(dang),外(wai)形規(gui)則的試樣。當(dang)檢驗試樣的表(biao)層組織時,為防(fang)止(zhi)在磨(mo)(mo)制中產生倒(dao)角,也(ye)可采用鑲嵌(qian)。一(yi)般取樣后用銼刀或砂輪(lun)將磨(mo)(mo)面修平,便可進行鑲嵌(qian)。常(chang)用的鑲嵌(qian)方(fang)法(fa)有(you)機械夾持法(fa),塑料鑲嵌(qian)法(fa)和低熔(rong)點合(he)金(jin)鑲嵌(qian)法(fa)等。
3. 磨光
金相試樣(yang)經過(guo)取樣(yang)、鑲嵌后(hou),還需進行磨(mo)(mo)(mo)光(guang)、拋(pao)光(guang)等工序(xu),才(cai)能(neng)獲得表面平整光(guang)滑(hua)的磨(mo)(mo)(mo)面。試樣(yang)切取后(hou)形(xing)成的粗(cu)(cu)糙表面,經過(guo)粗(cu)(cu)磨(mo)(mo)(mo)、細(xi)磨(mo)(mo)(mo)、拋(pao)光(guang)工序(xu)后(hou),磨(mo)(mo)(mo)痕逐漸消除,從而得到平整光(guang)滑(hua)的磨(mo)(mo)(mo)面。
4. 拋光
拋(pao)(pao)光后的試樣表(biao)面呈現(xian)(xian)出(chu)平滑光亮、無痕(hen)鏡(jing)面狀態,置于金相顯(xian)(xian)(xian)(xian)微鏡(jing)下(xia)觀察(cha)時,除(chu)了(le)可(ke)以(yi)見(jian)到(dao)(dao)非金屬夾(jia)雜物、孔洞、裂紋、石墨和(he)(he)鉛(qian)青(qing)銅的鉛(qian)質點以(yi)及(ji)極(ji)硬相在(zai)拋(pao)(pao)光時的浮凸外,只(zhi)能看到(dao)(dao)一(yi)片光亮,看不到(dao)(dao)顯(xian)(xian)(xian)(xian)微組織(zhi)。只(zhi)有(you)采(cai)用適當的顯(xian)(xian)(xian)(xian)示(shi)(shi)方(fang)法,才能顯(xian)(xian)(xian)(xian)示(shi)(shi)出(chu)組織(zhi)。 顯(xian)(xian)(xian)(xian)示(shi)(shi)組織(zhi)的方(fang)法很多,可(ke)分為(wei)化學顯(xian)(xian)(xian)(xian)示(shi)(shi)、電解顯(xian)(xian)(xian)(xian)示(shi)(shi)和(he)(he)其它顯(xian)(xian)(xian)(xian)示(shi)(shi)方(fang)法。其中(zhong)化學顯(xian)(xian)(xian)(xian)示(shi)(shi)法具(ju)有(you)顯(xian)(xian)(xian)(xian)示(shi)(shi)全面,操作簡便,迅速、經濟、重現(xian)(xian)性(xing)好等優(you)點。在(zai)生產和(he)(he)科(ke)研中(zhong)得(de)到(dao)(dao)了(le)廣泛應(ying)用。
最后,上述金相試樣的制備,均需切取試樣,但某些大型機件、構件以及曲面、不銹(xiu)鋼管道內壁、斷口、放射性材料等,不允許破壞取樣檢驗,則可采用膠膜復型法,復制成薄膜樣品,可在金相顯微鏡或生物顯微鏡下觀察。
浙江至德鋼業有限公司專業生產不銹鋼管及管道連接配件廠家,倉庫常備不銹鋼管庫存1000余噸及部分不銹鋼法蘭管件(彎頭|三通|大小頭)現貨,常用規格可當天發貨。另可提供各種不銹鋼管切割、拋光、折彎、鉆孔、焊接、車床加工及管道預制件加工等配套服務。

