20號無縫鋼管在(zai)100℃與225℃溫度(temperature)的許應力的區別(bie)
20號鋼許用(yong)應力(li)：20號鋼在225℃下的許用(yong)應力(li)：(16-36mm)111-124MPa之(zhi)間;(6-16mm)之(zhi)間117-131MPa
20號(hao)鋼在100℃下的許(xu)用(yong)應(ying)力(li)：150℃時,20號(hao)鋼鋼管的許(xu)用(yong)應(ying)力(li)為130 MPa,20號(hao)鋼鍛(duan)件的許(xu)用(yong)應(ying)力(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(de)碳(tan)(C)素結(jie)構(Structure)鋼、低合金結(jie)構鋼或合金結(jie)構鋼軋制，產量(liang)最多(duo)，主要(yao)用作輸送流體的(de)管道或結(jie)構零件。2、根據用途不(bu)同(tong)分三類供應：
A、按(an)化學(Chemistry)成分(ingredient)和機械(machinery)性能(xìng néng)供應;
B、按(an)機械(machinery)性(xing)能(neng)(xìng néng)供應;
C、按(an)水壓(ya)試(shi)驗供(gong)應。GB9948無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan)主要(yao)用來生產氣(qi)動(dong)或(huo)液(ye)壓(ya) 元(yuan)件的產品(pin)，如氣(qi)缸(gang)或(huo)油缸(gang)，都是用無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)管(guan)(guan)。精密無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan)的化學成(cheng)分(fen)有(you)碳C、硅Si、錳Mn、硫S、磷P、鉻Cr。GB5310無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan)按(an)照用途分(fen)為結構用無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan);輸送用無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan);鍋爐(lu)用無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan);鍋爐(lu)用高壓(ya)無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan).無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan)按(an)照斷面(mian)形狀，無(wu)(wu)(wu)(wu)(wu)(wu)縫(feng)(feng)鋼(gang)(gang)管(guan)(guan)分(fen)圓(yuan)形和異形兩種，異形管(guan)(guan)有(you)方(fang)形、橢圓(yuan)形、三角形、六角形、瓜子形、星形、 帶翅管(guan)(guan)多種復雜(za)形狀。按(an)
A、b類供應(ying)的(de)鋼管(guan)(guan)，如用(yong)于承(cheng)受液體(ti)壓力(pressure)，也(ye)要進(jin)行(xing)水壓(特指:壓強)試驗。3、專門用(yong)途的(de)無(wu)(wu)縫(feng)(feng)管(guan)(guan)有鍋爐(Boilers)用(yong)無(wu)(wu)縫(feng)(feng)管(guan)(guan)、化工(gong)電(dian)力用(yong)，地質(zhi)用(yong)無(wu)(wu)縫(feng)(feng)鋼管(guan)(guan)及(ji)石油(petroleum)用(yong)無(wu)(wu)縫(feng)(feng)管(guan)(guan)等(deng)多種。 無(wu)(wu)縫(feng)(feng)鋼管(guan)(guan)具(ju)有中(zhong)空(zhōng kōng)截面，大量(liang)用(yong)作輸送流體(ti)的(de)管(guan)(guan)道(Conduit)，如輸送石油、天然(ran)(natural)氣、煤氣(Coal Gas)、水及(ji)某些(xie)固體(ti)物料(liao)的(de)管(guan)(guan)道等(deng)。鋼管(guan)(guan)與圓(yuan)鋼等(deng)實(shi)心鋼材(cai)相比，在(zai)抗彎(wan)抗扭(niu)強度(du)(strength)相同時(shi)，重量(liang)較輕，是一種經濟(Economy)截面鋼材(cai)。 廣(guang)泛(extensive)用(yong)于制(zhi)造(zhì zào)結(jie)構(gou)(Structure)件(jian)和機械(xie)(machinery)零件(jian)，如石油鉆桿、汽車(auto)傳(chuan)(chuan)動(dong)(dong)軸(傳(chuan)(chuan)動(dong)(dong)軸組成:軸管(guan)(guan)、伸縮套和萬向節(jie))、自行(xing)車架以及(ji)建筑(Architecture)施工(gong)中(zhong)用(yong)的(de)鋼腳手架等(deng)用(yong)鋼管(guan)(guan)制(zhi)造環形零件(jian)，可(ke)提高材(cai)料(liao)(Material)利(li)用(yong)率(lv)(availability)，簡化制(zhi)造工(gong)序，節(jie)約材(cai)料(liao)和加工(gong)(Processing)工(gong)時(shi)，已廣(guang)泛用(yong)鋼管(guan)(guan)來(lai)制(zhi)造。
