銅合金具有(you)(you)較高(gao)的(de)強度和(he)塑性(xing),具有(you)(you)高(gao)的(de)彈性(xing)極(ji)限(xian)和(he)疲勞極(ji)限(xian),同時還(huan)具有(you)(you)較好(hao)的(de)耐蝕性(xing)、抗堿性(xing)及(ji)優良的(de)減摩性(xing)和(he)耐磨性(xing)。銅又分純銅(俗(su)稱(cheng)紫銅)、黃(huang)銅和(he)青銅等。
1. 純銅(tong)
純(chun)銅(tong)面呈(cheng)紫紅色,有(you)良好的導電性(xing)、導熱(re)性(xing)和耐(nai)大氣腐蝕性(xing),熔點為(wei)(wei)(wei)1083℃。在管(guan)道(dao)工程中(zhong)常用(yong)純(chun)銅(tong)制成鋼管(guan)和法蘭墊片(pian)。因純(chun)銅(tong)硬度較低,退火后變得更柔軟,故(gu)常用(yong)作高壓管(guan)道(dao)中(zhong)的法蘭墊片(pian)。純(chun)銅(tong)管(guan)的低溫性(xing)能比鋼材好,故(gu)純(chun)銅(tong)管(guan)常用(yong)于空(kong)分設備管(guan)道(dao)、冷凍管(guan)道(dao)和儀表管(guan)道(dao)。純(chun)銅(tong)的高溫性(xing)能差,在120℃以下(xia)(xia),容(rong)許抗拉強度為(wei)(wei)(wei)29.43MPa。溫度若再升高,其機械強度則(ze)急劇下(xia)(xia)降,當(dang)溫度上升至250℃時(shi),其容(rong)許抗拉強度只相當(dang)于常溫時(shi)的2/3,已(yi)不(bu)宜在壓力(li)下(xia)(xia)使用(yong)。常用(yong)的純(chun)銅(tong)牌號為(wei)(wei)(wei)T2、T3、T4,雜質(zhi)含量T2最少,T4最多。
2. 黃銅(H)(brass)(H)
黃(huang)銅(tong)是(shi)銅(tong)和(he)鋅的合金,其機械(xie)強(qiang)(qiang)度(du)(du)高,有較好的耐腐蝕性和(he)澆鑄性,可(ke)(ke)用來(lai)制作管(guan)子、管(guan)件(jian)和(he)閥門等。化(hua)工上常(chang)用的有H80、H68、H62(“H”是(shi)黃(huang)銅(tong)代號(hao),后邊的數(shu)字表示合金中(zhong)銅(tong)的平(ping)均含量(liang))。H80比H68塑性好。作強(qiang)(qiang)度(du)(du)計(ji)算(suan)時(shi)(shi),在120℃以下,黃(huang)銅(tong)容許抗拉強(qiang)(qiang)度(du)(du)為29.43MPa。隨(sui)著溫度(du)(du)升高,其強(qiang)(qiang)度(du)(du)則(ze)急(ji)劇下降(jiang),當溫度(du)(du)沒超(chao)過225℃時(shi)(shi),黃(huang)銅(tong)閥件(jian)可(ke)(ke)用在壓(ya)力不超(chao)過1.6MPa的管(guan)道(dao)中(zhong)。
3. 青銅(bronze)(Q)
青(qing)(qing)銅(tong)(tong)(tong)是銅(tong)(tong)(tong)和錫的(de)(de)(de)合金,又稱錫青(qing)(qing)銅(tong)(tong)(tong)。由于錫的(de)(de)(de)價格較高,故制造青(qing)(qing)銅(tong)(tong)(tong)也(ye)常(chang)用其他元素(su)代替,因(yin)而又有無錫青(qing)(qing)銅(tong)(tong)(tong),如鋁(lv)青(qing)(qing)銅(tong)(tong)(tong)、鉛青(qing)(qing)銅(tong)(tong)(tong)、硅青(qing)(qing)銅(tong)(tong)(tong)等。青(qing)(qing)銅(tong)(tong)(tong)通常(chang)由澆鑄而成,其強度、硬度及耐腐蝕性都比黃(huang)銅(tong)(tong)(tong)好(hao)。青(qing)(qing)銅(tong)(tong)(tong)常(chang)用于制造蝸輪(lun)、齒輪(lun)、輪(lun),以(yi)及管(guan)道工程中(zhong)的(de)(de)(de)閥件和管(guan)件等。
例如,制(zhi)冷系統空調器用銅配管(guan)(guan)的材(cai)料(liao)為(wei)(wei)磷脫氧無(wu)縫拉制(zhi)銅管(guan)(guan),牌號(hao)為(wei)(wei)TP2(GB/T 5231),供應(ying)(ying)狀態有M(軟)、Y(硬),材(cai)料(liao)標(biao)記方法分(fen)別(bie)為(wei)(wei)TP2M,TP2Y。對(dui)應(ying)(ying)日本牌號(hao)分(fen)別(bie)為(wei)(wei)C1220T-OL,C1220-H。要求使用內(nei)表面無(wu)氧化的光亮管(guan)(guan)。其(qi)直徑、壁(bi)厚可(ke)參照GB/T 1804。其(qi)化學(xue)成分(fen)分(fen)析方法按(an)GB/T 5121進(jin)行,性(xing)能可(ke)按(an)GB/T 228、GB/T 242、GB/T 246。

