銅(tong)合(he)金(jin)具有較(jiao)高(gao)的(de)強度和(he)塑性(xing),具有高(gao)的(de)彈(dan)性(xing)極(ji)(ji)限(xian)和(he)疲勞極(ji)(ji)限(xian),同(tong)時(shi)還具有較(jiao)好的(de)耐(nai)蝕性(xing)、抗堿(jian)性(xing)及優良的(de)減摩性(xing)和(he)耐(nai)磨性(xing)。銅(tong)又分純銅(tong)(俗稱(cheng)紫(zi)銅(tong))、黃(huang)銅(tong)和(he)青(qing)銅(tong)等。
1. 純銅
純(chun)銅(tong)面呈(cheng)紫(zi)紅色,有良(liang)好(hao)的導電性、導熱性和耐大氣腐蝕性,熔點為1083℃。在管(guan)道(dao)(dao)工程中(zhong)常(chang)用(yong)純(chun)銅(tong)制(zhi)成鋼管(guan)和法蘭墊(dian)片。因(yin)純(chun)銅(tong)硬度較(jiao)低,退火后變得更柔軟,故常(chang)用(yong)作高(gao)壓管(guan)道(dao)(dao)中(zhong)的法蘭墊(dian)片。純(chun)銅(tong)管(guan)的低溫性能(neng)比鋼材好(hao),故純(chun)銅(tong)管(guan)常(chang)用(yong)于空分設備管(guan)道(dao)(dao)、冷凍管(guan)道(dao)(dao)和儀表管(guan)道(dao)(dao)。純(chun)銅(tong)的高(gao)溫性能(neng)差,在120℃以下,容許(xu)抗(kang)拉(la)強度為29.43MPa。溫度若再升(sheng)高(gao),其機械強度則(ze)急劇下降,當(dang)溫度上(shang)升(sheng)至250℃時(shi),其容許(xu)抗(kang)拉(la)強度只相當(dang)于常(chang)溫時(shi)的2/3,已不宜在壓力下使用(yong)。常(chang)用(yong)的純(chun)銅(tong)牌號為T2、T3、T4,雜質含量T2最(zui)少,T4最(zui)多。
2. 黃銅(tong)(H)(brass)(H)
黃(huang)(huang)銅(tong)是(shi)銅(tong)和(he)鋅的(de)合金,其機(ji)械強(qiang)(qiang)度(du)高(gao),有(you)較(jiao)好的(de)耐(nai)腐蝕(shi)性(xing)(xing)和(he)澆鑄(zhu)性(xing)(xing),可(ke)用(yong)(yong)來(lai)制作管子、管件和(he)閥門(men)等。化工上常用(yong)(yong)的(de)有(you)H80、H68、H62(“H”是(shi)黃(huang)(huang)銅(tong)代號,后邊的(de)數字(zi)表示合金中銅(tong)的(de)平均含量)。H80比H68塑性(xing)(xing)好。作強(qiang)(qiang)度(du)計算時(shi),在(zai)120℃以(yi)下(xia),黃(huang)(huang)銅(tong)容許抗(kang)拉(la)強(qiang)(qiang)度(du)為29.43MPa。隨著(zhu)溫度(du)升高(gao),其強(qiang)(qiang)度(du)則急劇下(xia)降,當溫度(du)沒(mei)超過(guo)225℃時(shi),黃(huang)(huang)銅(tong)閥件可(ke)用(yong)(yong)在(zai)壓(ya)力不超過(guo)1.6MPa的(de)管道(dao)中。
3. 青銅(bronze)(Q)
青(qing)銅(tong)(tong)是銅(tong)(tong)和(he)錫(xi)(xi)的合金,又(you)稱(cheng)錫(xi)(xi)青(qing)銅(tong)(tong)。由(you)于錫(xi)(xi)的價格較高,故制造(zao)(zao)青(qing)銅(tong)(tong)也常(chang)用其他元素代替(ti),因而又(you)有無(wu)錫(xi)(xi)青(qing)銅(tong)(tong),如(ru)鋁青(qing)銅(tong)(tong)、鉛青(qing)銅(tong)(tong)、硅青(qing)銅(tong)(tong)等。青(qing)銅(tong)(tong)通常(chang)由(you)澆鑄而成,其強度(du)、硬度(du)及耐腐蝕(shi)性都(dou)比黃銅(tong)(tong)好。青(qing)銅(tong)(tong)常(chang)用于制造(zao)(zao)蝸輪、齒輪、輪,以及管道工程中的閥(fa)件(jian)和(he)管件(jian)等。
例(li)如,制冷系統空調器用銅(tong)配管(guan)的材(cai)料為(wei)(wei)磷(lin)脫氧無縫拉制銅(tong)管(guan),牌號為(wei)(wei)TP2(GB/T 5231),供應狀態有M(軟)、Y(硬),材(cai)料標(biao)記方法分(fen)別為(wei)(wei)TP2M,TP2Y。對應日本牌號分(fen)別為(wei)(wei)C1220T-OL,C1220-H。要(yao)求使用內表面無氧化(hua)(hua)的光(guang)亮管(guan)。其直徑(jing)、壁厚可參(can)照(zhao)GB/T 1804。其化(hua)(hua)學成分(fen)分(fen)析(xi)方法按GB/T 5121進(jin)行,性能可按GB/T 228、GB/T 242、GB/T 246。