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鍋爐(lu)合(he)金(jin)管件(jian)硬度的檢測方法

   1、鍋(guo)爐合金管件熱(re)處理(li)工(gong)件的硬(ying)(ying)度使用(yong)硬(ying)(ying)度計(ji)檢測(ce)。PHR系列便攜式表(biao)面(mian)洛氏(shi)硬(ying)(ying)度計(ji)十分適用(yong)于檢測(ce)表(biao)面(mian)熱(re)處理(li)工(gong)件的硬(ying)(ying)度，可以測(ce)試有效化深度超過0.1mm的各種(zhong)表(biao)面(mian)熱(re)處理(li)工(gong)件。操作簡單、使用(yong)方(fang)便、價格較低，可直接讀取硬(ying)(ying)度值。

    2、鍋爐合(he)金管件表(biao)(biao)面(mian)熱處(chu)理分為兩大(da)類，一(yi)類是表(biao)(biao)面(mian)淬火(huo)回(hui)火(huo)熱處(chu)理，另(ling)一(yi)類是化(hua)學(xue)熱處(chu)理，其硬(ying)度檢驗方法如下：化(hua)學(xue)熱處(chu)理是使工(gong)件表(biao)(biao)面(mian)滲入一(yi)種或幾種化(hua)學(xue)元素(su)的原子，從而(er)改變(bian)工(gong)件表(biao)(biao)面(mian)的化(hua)學(xue)成分、組織和性能。經(jing)淬火(huo)和低(di)溫(wen)回(hui)火(huo)后，工(gong)件表(biao)(biao)面(mian)具(ju)有(you)高(gao)的硬(ying)度、耐磨性和接觸(chu)疲勞強度，而(er)工(gong)件的芯部又具(ju)有(you)高(gao)的強韌(ren)性。

    3、鍋(guo)爐合金管(guan)件(jian)(jian)(jian)化(hua)(hua)(hua)(hua)學熱(re)(re)處理(li)工件(jian)(jian)(jian)的(de)主要(yao)技術參(can)數(shu)是(shi)硬(ying)(ying)化(hua)(hua)(hua)(hua)層(ceng)深(shen)(shen)度(du)(du)(du)(du)(du)和表(biao)(biao)面硬(ying)(ying)度(du)(du)(du)(du)(du)。硬(ying)(ying)化(hua)(hua)(hua)(hua)層(ceng)深(shen)(shen)度(du)(du)(du)(du)(du)還(huan)是(shi)要(yao)用(yong)(yong)維(wei)氏(shi)(shi)(shi)硬(ying)(ying)度(du)(du)(du)(du)(du)計(ji)(ji)(ji)來檢(jian)(jian)測(ce)(ce)。檢(jian)(jian)測(ce)(ce)從工件(jian)(jian)(jian)表(biao)(biao)面到硬(ying)(ying)度(du)(du)(du)(du)(du)降到50HRC那一(yi)點的(de)距離。這就是(shi)有效硬(ying)(ying)化(hua)(hua)(hua)(hua)深(shen)(shen)度(du)(du)(du)(du)(du)化(hua)(hua)(hua)(hua)學熱(re)(re)處理(li)工件(jian)(jian)(jian)的(de)表(biao)(biao)面硬(ying)(ying)度(du)(du)(du)(du)(du)檢(jian)(jian)測(ce)(ce)與表(biao)(biao)面淬(cui)(cui)火熱(re)(re)處理(li)工件(jian)(jian)(jian)的(de)硬(ying)(ying)度(du)(du)(du)(du)(du)檢(jian)(jian)測(ce)(ce)相(xiang)近，都(dou)可以用(yong)(yong)維(wei)氏(shi)(shi)(shi)硬(ying)(ying)度(du)(du)(du)(du)(du)計(ji)(ji)(ji)、表(biao)(biao)面洛(luo)(luo)氏(shi)(shi)(shi)硬(ying)(ying)度(du)(du)(du)(du)(du)計(ji)(ji)(ji)或洛(luo)(luo)氏(shi)(shi)(shi)硬(ying)(ying)度(du)(du)(du)(du)(du)計(ji)(ji)(ji)來檢(jian)(jian)測(ce)(ce)，只是(shi)滲氮(dan)厚(hou)的(de)厚(hou)度(du)(du)(du)(du)(du)較(jiao)薄，一(yi)般不大于0.7mm，這時(shi)就不能再采用(yong)(yong)洛(luo)(luo)氏(shi)(shi)(shi)硬(ying)(ying)度(du)(du)(du)(du)(du)計(ji)(ji)(ji)了。零(ling)件(jian)(jian)(jian)如果局(ju)(ju)部硬(ying)(ying)度(du)(du)(du)(du)(du)要(yao)求較(jiao)高，可用(yong)(yong)感應加熱(re)(re)等方(fang)式進(jin)行局(ju)(ju)部淬(cui)(cui)火熱(re)(re)處理(li)，這樣的(de)零(ling)件(jian)(jian)(jian)通常(chang)要(yao)在圖(tu)紙上標(biao)出局(ju)(ju)部淬(cui)(cui)火熱(re)(re)處理(li)的(de)位置和局(ju)(ju)部硬(ying)(ying)度(du)(du)(du)(du)(du)值(zhi)(zhi)。零(ling)件(jian)(jian)(jian)的(de)硬(ying)(ying)度(du)(du)(du)(du)(du)檢(jian)(jian)測(ce)(ce)要(yao)在指(zhi)定區(qu)域內(nei)進(jin)行。硬(ying)(ying)度(du)(du)(du)(du)(du)檢(jian)(jian)測(ce)(ce)儀(yi)器可采用(yong)(yong)洛(luo)(luo)氏(shi)(shi)(shi)硬(ying)(ying)度(du)(du)(du)(du)(du)計(ji)(ji)(ji)，測(ce)(ce)試(shi)HRC硬(ying)(ying)度(du)(du)(du)(du)(du)值(zhi)(zhi)，如熱(re)(re)處理(li)硬(ying)(ying)化(hua)(hua)(hua)(hua)層(ceng)較(jiao)淺(qian)，可采用(yong)(yong)表(biao)(biao)面洛(luo)(luo)氏(shi)(shi)(shi)硬(ying)(ying)度(du)(du)(du)(du)(du)計(ji)(ji)(ji)，測(ce)(ce)試(shi)HRN硬(ying)(ying)度(du)(du)(du)(du)(du)值(zhi)(zhi)。

    4、鍋爐合金管件表面淬火回火熱處理通常用感應加熱或火焰加熱的方式進行。主要技術參數是表面硬度、局部硬度和有效硬化層深度。硬度檢測可采用維氏硬度計，也可采用洛氏或表面洛氏硬度計。試驗力（標尺）的選擇與有效硬化層深度和工件表面硬度有關。這里涉及到三種硬度計。維氏硬度計是測試熱處理工件表面硬度的重要手段，它可選用0.5～100kg的試驗力，測試薄至0.05mm厚的表面硬化層，它精度高，可分(fen)辨(bian)出工件表(biao)面硬(ying)度(du)的(de)微小(xiao)差別。另外，有效硬(ying)化(hua)層(ceng)深(shen)度(du)也要由維氏硬(ying)度(du)計來檢測(ce)，所以，對于(yu)進(jin)行表(biao)面熱(re)處理加工或大(da)量使用表(biao)面熱(re)處理工件的(de)單位，配(pei)備(bei)一臺維氏硬(ying)度(du)計是(shi)有必(bi)要的(de)。

   5、鍋爐合(he)(he)金管(guan)(guan)件(jian)(jian)表(biao)面洛(luo)氏(shi)(shi)硬(ying)(ying)(ying)(ying)度(du)(du)計也是十分適于測(ce)(ce)試表(biao)面淬(cui)火工(gong)件(jian)(jian)硬(ying)(ying)(ying)(ying)度(du)(du)的，表(biao)面洛(luo)氏(shi)(shi)硬(ying)(ying)(ying)(ying)度(du)(du)計有(you)(you)三種(zhong)標(biao)尺(chi)可(ke)(ke)以(yi)選擇(ze)。可(ke)(ke)以(yi)測(ce)(ce)試有(you)(you)效(xiao)硬(ying)(ying)(ying)(ying)化(hua)(hua)深(shen)度(du)(du)超(chao)過(guo)0.1mm的各(ge)種(zhong)表(biao)面硬(ying)(ying)(ying)(ying)化(hua)(hua)工(gong)件(jian)(jian)。盡管(guan)(guan)表(biao)面洛(luo)氏(shi)(shi)硬(ying)(ying)(ying)(ying)度(du)(du)計的精度(du)(du)沒有(you)(you)維氏(shi)(shi)硬(ying)(ying)(ying)(ying)度(du)(du)計高(gao)，但是作為熱處理(li)工(gong)廠質量(liang)管(guan)(guan)理(li)和合(he)(he)格(ge)(ge)檢(jian)(jian)查的檢(jian)(jian)測(ce)(ce)手段，已(yi)經能夠(gou)滿(man)足要求。況且它還具(ju)有(you)(you)操作簡單、使用方便(bian)、價格(ge)(ge)較低，測(ce)(ce)量(liang)迅速(su)、可(ke)(ke)直接讀取硬(ying)(ying)(ying)(ying)度(du)(du)值等特點(dian)，利(li)用表(biao)面洛(luo)氏(shi)(shi)硬(ying)(ying)(ying)(ying)度(du)(du)計可(ke)(ke)對成批的表(biao)面熱處理(li)工(gong)件(jian)(jian)進行快速(su)無損(sun)的逐件(jian)(jian)檢(jian)(jian)測(ce)(ce)。這一(yi)點(dian)對于金屬加工(gong)和機械制造工(gong)廠具(ju)有(you)(you)重(zhong)要意義。當表(biao)面熱處理(li)硬(ying)(ying)(ying)(ying)化(hua)(hua)層(ceng)(ceng)較厚時，也可(ke)(ke)采(cai)用洛(luo)氏(shi)(shi)硬(ying)(ying)(ying)(ying)度(du)(du)計。當硬(ying)(ying)(ying)(ying)化(hua)(hua)層(ceng)(ceng)厚度(du)(du)在0.4～0.8mm時，可(ke)(ke)采(cai)用HRA標(biao)尺(chi)，當硬(ying)(ying)(ying)(ying)化(hua)(hua)層(ceng)(ceng)厚度(du)(du)超(chao)過(guo)0.8mm時，可(ke)(ke)采(cai)用HRC標(biao)尺(chi)。

    6、鍋爐合金管件(jian)維(wei)氏(shi)、洛(luo)氏(shi)和表面(mian)洛(luo)氏(shi)三種硬度值(zhi)可以方便地進行(xing)相(xiang)互換(huan)算，轉換(huan)成標(biao)(biao)準(zhun)、圖紙或(huo)用戶(hu)需要的硬度值(zhi)。相(xiang)應的換(huan)算表在國(guo)際標(biao)(biao)準(zhun)ISO、美國(guo)標(biao)(biao)準(zhun)ASTM和中國(guo)標(biao)(biao)準(zhun)GB/T中都(dou)已給出。