20號無縫鋼管在100℃與225℃溫(wen)度(temperature)的許(xu)應力的區(qu)別
20號鋼許用(yong)應力：20號鋼在225℃下的許用(yong)應力：(16-36mm)111-124MPa之間;(6-16mm)之間117-131MPa
20號鋼(gang)(gang)在100℃下的許用(yong)應力：150℃時,20號鋼(gang)(gang)鋼(gang)(gang)管的許用(yong)應力為130 MPa,20號鋼(gang)(gang)鍛件的許用(yong)應力為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)素結(jie)(jie)構(Structure)鋼、低合(he)金結(jie)(jie)構鋼或(huo)合(he)金結(jie)(jie)構鋼軋制，產量最多，主要用作輸(shu)送流體(ti)的管道或(huo)結(jie)(jie)構零件。2、根據用途(tu)不(bu)同(tong)分三類(lei)供(gong)應：
A、按化學(Chemistry)成分(ingredient)和機械(machinery)性能(xìng néng)供應;
B、按機(ji)械(machinery)性(xing)能(xìng néng)供(gong)應;
C、按(an)水壓(ya)試驗(yan)供應。GB9948無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan)主要用(yong)(yong)來生產(chan)氣(qi)動或液壓(ya) 元件的(de)產(chan)品，如(ru)氣(qi)缸或油缸，都是(shi)用(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)管(guan)(guan)。精密無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan)的(de)化(hua)學成分(fen)有(you)碳(tan)C、硅Si、錳Mn、硫(liu)S、磷(lin)P、鉻Cr。GB5310無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan)按(an)照(zhao)用(yong)(yong)途分(fen)為結構用(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan);輸送用(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan);鍋(guo)爐(lu)(lu)用(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan);鍋(guo)爐(lu)(lu)用(yong)(yong)高壓(ya)無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan).無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan)按(an)照(zhao)斷(duan)面形(xing)(xing)(xing)(xing)狀，無(wu)(wu)(wu)縫(feng)(feng)(feng)(feng)鋼(gang)(gang)管(guan)(guan)分(fen)圓形(xing)(xing)(xing)(xing)和異形(xing)(xing)(xing)(xing)兩(liang)種，異形(xing)(xing)(xing)(xing)管(guan)(guan)有(you)方形(xing)(xing)(xing)(xing)、橢圓形(xing)(xing)(xing)(xing)、三角形(xing)(xing)(xing)(xing)、六角形(xing)(xing)(xing)(xing)、瓜(gua)子形(xing)(xing)(xing)(xing)、星(xing)形(xing)(xing)(xing)(xing)、 帶翅(chi)管(guan)(guan)多種復雜(za)形(xing)(xing)(xing)(xing)狀。按(an)
A、b類供應的(de)(de)鋼(gang)(gang)管(guan)(guan)，如(ru)用(yong)(yong)(yong)(yong)于(yu)承受液體(ti)壓力(li)(li)(pressure)，也要進行水壓(特指:壓強)試驗。3、專(zhuan)門用(yong)(yong)(yong)(yong)途的(de)(de)無(wu)縫(feng)管(guan)(guan)有鍋爐(Boilers)用(yong)(yong)(yong)(yong)無(wu)縫(feng)管(guan)(guan)、化工(gong)電力(li)(li)用(yong)(yong)(yong)(yong)，地(di)質用(yong)(yong)(yong)(yong)無(wu)縫(feng)鋼(gang)(gang)管(guan)(guan)及石油(you)(you)(petroleum)用(yong)(yong)(yong)(yong)無(wu)縫(feng)管(guan)(guan)等(deng)多種(zhong)。 無(wu)縫(feng)鋼(gang)(gang)管(guan)(guan)具有中空(zhōng kōng)截面(mian)，大量用(yong)(yong)(yong)(yong)作(zuo)輸(shu)送流(liu)體(ti)的(de)(de)管(guan)(guan)道(Conduit)，如(ru)輸(shu)送石油(you)(you)、天然(natural)氣、煤氣(Coal Gas)、水及某些(xie)固(gu)體(ti)物料(liao)的(de)(de)管(guan)(guan)道等(deng)。鋼(gang)(gang)管(guan)(guan)與(yu)圓鋼(gang)(gang)等(deng)實心鋼(gang)(gang)材相比，在抗彎(wan)抗扭強度(du)(strength)相同時，重(zhong)量較輕，是一種(zhong)經濟(Economy)截面(mian)鋼(gang)(gang)材。 廣泛(extensive)用(yong)(yong)(yong)(yong)于(yu)制(zhi)造(zao)(zhì zào)結構(gou)(Structure)件和機械(machinery)零(ling)件，如(ru)石油(you)(you)鉆桿、汽車(auto)傳(chuan)動軸(zhou)(傳(chuan)動軸(zhou)組成:軸(zhou)管(guan)(guan)、伸縮套(tao)和萬(wan)向節)、自行車架以及建筑(Architecture)施工(gong)中用(yong)(yong)(yong)(yong)的(de)(de)鋼(gang)(gang)腳手(shou)架等(deng)用(yong)(yong)(yong)(yong)鋼(gang)(gang)管(guan)(guan)制(zhi)造(zao)環形零(ling)件，可提高材料(liao)(Material)利用(yong)(yong)(yong)(yong)率(availability)，簡化制(zhi)造(zao)工(gong)序，節約材料(liao)和加(jia)工(gong)(Processing)工(gong)時，已廣泛用(yong)(yong)(yong)(yong)鋼(gang)(gang)管(guan)(guan)來制(zhi)造(zao)。
