20號無縫鋼管在100℃與225℃溫(wen)度(du)(temperature)的(de)(de)許應力的(de)(de)區(qu)別
20號鋼許用應力：20號鋼在225℃下的許用應力：(16-36mm)111-124MPa之間(jian);(6-16mm)之間(jian)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130 MPa,20號鋼(gang)鍛件的許用應力(li)(li)為108MPa
無縫鋼管用途很廣泛(extensive)。一般用途的無縫鋼管由普通的碳(tan)(C)素(su)結(jie)構(Structure)鋼、低(di)合金(jin)(jin)結(jie)構鋼或合金(jin)(jin)結(jie)構鋼軋制，產量最多，主要用作輸(shu)送流體的管道或結(jie)構零件(jian)。2、根(gen)據用途不同分三類供應：
A、按化(hua)學(Chemistry)成分(ingredient)和機械(machinery)性能(xìng néng)供應;
B、按機械(machinery)性能(xìng néng)供應;
C、按(an)水壓試驗供應。GB9948無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管主要用(yong)(yong)來(lai)生產(chan)氣(qi)動或液壓 元(yuan)件的產(chan)品，如氣(qi)缸或油缸，都是用(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)管。精(jing)密無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管的化學成分(fen)有碳C、硅(gui)Si、錳Mn、硫S、磷P、鉻Cr。GB5310無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管按(an)照用(yong)(yong)途分(fen)為結構用(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管;輸送用(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管;鍋爐(lu)用(yong)(yong)無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管;鍋爐(lu)用(yong)(yong)高壓無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管.無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管按(an)照斷(duan)面形狀(zhuang)，無(wu)(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管分(fen)圓(yuan)形和異(yi)形兩種，異(yi)形管有方(fang)形、橢圓(yuan)形、三角形、六角形、瓜子形、星形、 帶翅(chi)管多種復雜形狀(zhuang)。按(an)
A、b類供應的鋼(gang)(gang)管(guan)(guan)，如用(yong)(yong)于承受液體壓(ya)力(pressure)，也要進(jin)行水壓(ya)(特指:壓(ya)強)試(shi)驗(yan)。3、專(zhuan)門(men)用(yong)(yong)途的無(wu)縫(feng)(feng)管(guan)(guan)有鍋爐(Boilers)用(yong)(yong)無(wu)縫(feng)(feng)管(guan)(guan)、化(hua)工(gong)電力用(yong)(yong)，地質用(yong)(yong)無(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan)及石油(you)(petroleum)用(yong)(yong)無(wu)縫(feng)(feng)管(guan)(guan)等(deng)多種(zhong)(zhong)。 無(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan)具有中(zhong)空(zhōng kōng)截面(mian)，大量(liang)用(yong)(yong)作輸送(song)流體的管(guan)(guan)道(Conduit)，如輸送(song)石油(you)、天(tian)然(natural)氣、煤氣(Coal Gas)、水及某些(xie)固體物料(liao)(liao)的管(guan)(guan)道等(deng)。鋼(gang)(gang)管(guan)(guan)與圓鋼(gang)(gang)等(deng)實心鋼(gang)(gang)材相(xiang)(xiang)比，在(zai)抗彎抗扭強度(du)(strength)相(xiang)(xiang)同時，重量(liang)較輕，是(shi)一種(zhong)(zhong)經濟(Economy)截面(mian)鋼(gang)(gang)材。 廣泛(extensive)用(yong)(yong)于制造(zao)(zhì zào)結構(Structure)件和機械(machinery)零件，如石油(you)鉆桿、汽車(auto)傳(chuan)動軸(zhou)(zhou)(傳(chuan)動軸(zhou)(zhou)組成:軸(zhou)(zhou)管(guan)(guan)、伸縮套和萬向節(jie)(jie))、自行車架(jia)(jia)以及建筑(Architecture)施(shi)工(gong)中(zhong)用(yong)(yong)的鋼(gang)(gang)腳(jiao)手(shou)架(jia)(jia)等(deng)用(yong)(yong)鋼(gang)(gang)管(guan)(guan)制造(zao)環形(xing)零件，可提高材料(liao)(liao)(Material)利用(yong)(yong)率(lv)(availability)，簡化(hua)制造(zao)工(gong)序，節(jie)(jie)約材料(liao)(liao)和加工(gong)(Processing)工(gong)時，已廣泛用(yong)(yong)鋼(gang)(gang)管(guan)(guan)來制造(zao)。
