20號無縫鋼管在100℃與225℃溫度(temperature)的(de)許應力的(de)區別
20號鋼許用應(ying)力(li)：20號鋼在(zai)225℃下的許用應(ying)力(li)：(16-36mm)111-124MPa之(zhi)(zhi)間;(6-16mm)之(zhi)(zhi)間117-131MPa
20號鋼(gang)在(zai)100℃下的許用應力(li)(li)：150℃時,20號鋼(gang)鋼(gang)管的許用應力(li)(li)為(wei)130 MPa,20號鋼(gang)鍛件的許用應力(li)(li)為(wei)108MPa
無縫鋼管用途很廣泛(extensive)。一般用途的無縫鋼管由普通的(de)碳(C)素結構(gou)(Structure)鋼、低合(he)金結構(gou)鋼或合(he)金結構(gou)鋼軋(ya)制(zhi)，產量最多，主要(yao)用(yong)作輸送流(liu)體的(de)管道或結構(gou)零(ling)件。2、根據用(yong)途不同(tong)分(fen)三類供(gong)應(ying)：
A、按化學(Chemistry)成(cheng)分(ingredient)和機械(machinery)性能(neng)(xìng néng)供應(ying);
B、按機(ji)械(machinery)性(xing)能(xìng néng)供應(ying);
C、按水壓試驗供應。GB9948無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)主要用來(lai)生產氣動或(huo)(huo)液壓 元件的產品，如氣缸或(huo)(huo)油缸，都是用無(wu)(wu)縫(feng)(feng)(feng)管(guan)(guan)(guan)(guan)(guan)。精密無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)的化學成分有碳C、硅Si、錳Mn、硫S、磷P、鉻Cr。GB5310無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)按照(zhao)用途分為結構(gou)用無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan);輸送用無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan);鍋(guo)爐用無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan);鍋(guo)爐用高壓無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan).無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)按照(zhao)斷面形(xing)(xing)狀，無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)分圓(yuan)形(xing)(xing)和異(yi)形(xing)(xing)兩種(zhong)，異(yi)形(xing)(xing)管(guan)(guan)(guan)(guan)(guan)有方形(xing)(xing)、橢圓(yuan)形(xing)(xing)、三角形(xing)(xing)、六角形(xing)(xing)、瓜子(zi)形(xing)(xing)、星形(xing)(xing)、 帶翅管(guan)(guan)(guan)(guan)(guan)多種(zhong)復雜形(xing)(xing)狀。按
A、b類供(gong)應的(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)，如(ru)用(yong)于承受液體壓力(pressure)，也要(yao)進行水壓(特指:壓強)試(shi)驗。3、專門(men)用(yong)途的(de)(de)無縫管(guan)(guan)(guan)(guan)(guan)(guan)(guan)有鍋(guo)爐(Boilers)用(yong)無縫管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、化(hua)工(gong)電力用(yong)，地質用(yong)無縫鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)及(ji)石油(petroleum)用(yong)無縫管(guan)(guan)(guan)(guan)(guan)(guan)(guan)等多種。 無縫鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)具(ju)有中空(zhōng kōng)截(jie)面，大量用(yong)作輸(shu)(shu)送(song)流體的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(Conduit)，如(ru)輸(shu)(shu)送(song)石油、天然(natural)氣、煤氣(Coal Gas)、水及(ji)某些固體物(wu)料的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)道(dao)等。鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)與(yu)圓鋼(gang)(gang)(gang)等實(shi)心(xin)鋼(gang)(gang)(gang)材(cai)相(xiang)比(bi)，在抗彎(wan)抗扭強度(strength)相(xiang)同時，重量較輕，是一種經(jing)濟(Economy)截(jie)面鋼(gang)(gang)(gang)材(cai)。 廣(guang)泛(extensive)用(yong)于制造(zao)(zhì zào)結(jie)構(Structure)件(jian)(jian)和(he)機械(machinery)零件(jian)(jian)，如(ru)石油鉆桿(gan)、汽車(che)(che)(auto)傳動軸(zhou)(傳動軸(zhou)組成:軸(zhou)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)、伸縮套和(he)萬向節)、自(zi)行車(che)(che)架以(yi)及(ji)建筑(Architecture)施工(gong)中用(yong)的(de)(de)鋼(gang)(gang)(gang)腳手架等用(yong)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)制造(zao)環形零件(jian)(jian)，可提高材(cai)料(Material)利用(yong)率(availability)，簡化(hua)制造(zao)工(gong)序，節約(yue)材(cai)料和(he)加工(gong)(Processing)工(gong)時，已廣(guang)泛用(yong)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)來制造(zao)。
