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(yong)應力：20號鋼在225℃下的(de)許用(yong)應力：(16-36mm)111-124MPa之(zhi)間;(6-16mm)之(zhi)間117-131MPa
20號(hao)鋼在100℃下的許用應(ying)力(li)：150℃時,20號(hao)鋼鋼管的許用應(ying)力(li)為130 MPa,20號(hao)鋼鍛件的許用應(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)(de)碳(C)素結構(gou)(gou)(Structure)鋼(gang)(gang)、低合金結構(gou)(gou)鋼(gang)(gang)或(huo)合金結構(gou)(gou)鋼(gang)(gang)軋制，產量最(zui)多(duo)，主要用作輸送流體的(de)(de)管道或(huo)結構(gou)(gou)零件。2、根據用途(tu)不同分(fen)三類(lei)供應：
A、按(an)化學(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、按水(shui)壓(ya)試(shi)驗供應。GB9948無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan)主要用(yong)(yong)(yong)來(lai)生產氣動或液(ye)壓(ya) 元(yuan)件(jian)的(de)產品(pin)，如(ru)氣缸(gang)或油(you)缸(gang)，都是用(yong)(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)管(guan)(guan)。精密(mi)無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan)的(de)化學成分有碳C、硅Si、錳(meng)Mn、硫S、磷P、鉻Cr。GB5310無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan)按照用(yong)(yong)(yong)途分為結構(gou)用(yong)(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan);輸送(song)用(yong)(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan);鍋爐用(yong)(yong)(yong)無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan);鍋爐用(yong)(yong)(yong)高壓(ya)無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan).無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan)按照斷面形(xing)(xing)(xing)狀，無(wu)(wu)(wu)縫(feng)(feng)鋼(gang)管(guan)(guan)分圓形(xing)(xing)(xing)和異形(xing)(xing)(xing)兩種，異形(xing)(xing)(xing)管(guan)(guan)有方形(xing)(xing)(xing)、橢圓形(xing)(xing)(xing)、三角(jiao)形(xing)(xing)(xing)、六角(jiao)形(xing)(xing)(xing)、瓜(gua)子形(xing)(xing)(xing)、星(xing)形(xing)(xing)(xing)、 帶翅管(guan)(guan)多種復雜形(xing)(xing)(xing)狀。按
A、b類供(gong)應的(de)鋼(gang)管(guan)(guan)(guan)，如用(yong)(yong)(yong)于承(cheng)受液體(ti)(ti)壓力(pressure)，也(ye)要進行(xing)水壓(特指(zhi):壓強)試驗。3、專門用(yong)(yong)(yong)途的(de)無(wu)縫管(guan)(guan)(guan)有鍋爐(Boilers)用(yong)(yong)(yong)無(wu)縫管(guan)(guan)(guan)、化(hua)工(gong)(gong)電力用(yong)(yong)(yong)，地質用(yong)(yong)(yong)無(wu)縫鋼(gang)管(guan)(guan)(guan)及石油(you)(you)(petroleum)用(yong)(yong)(yong)無(wu)縫管(guan)(guan)(guan)等多種(zhong)。 無(wu)縫鋼(gang)管(guan)(guan)(guan)具有中空(zhōng kōng)截(jie)面(mian)，大量(liang)用(yong)(yong)(yong)作輸送(song)流體(ti)(ti)的(de)管(guan)(guan)(guan)道(Conduit)，如輸送(song)石油(you)(you)、天然(natural)氣(qi)、煤氣(qi)(Coal Gas)、水及某些固(gu)體(ti)(ti)物料的(de)管(guan)(guan)(guan)道等。鋼(gang)管(guan)(guan)(guan)與圓鋼(gang)等實心(xin)鋼(gang)材相比，在抗(kang)彎抗(kang)扭強度(strength)相同時，重量(liang)較輕，是(shi)一種(zhong)經濟(Economy)截(jie)面(mian)鋼(gang)材。 廣泛(extensive)用(yong)(yong)(yong)于制(zhi)(zhi)(zhi)造(zao)(zao)(zao)(zhì zào)結構(Structure)件和機械(xie)(machinery)零件，如石油(you)(you)鉆(zhan)桿、汽車(auto)傳(chuan)動軸(zhou)(傳(chuan)動軸(zhou)組成:軸(zhou)管(guan)(guan)(guan)、伸縮套和萬向(xiang)節(jie))、自行(xing)車架(jia)以(yi)及建筑(Architecture)施工(gong)(gong)中用(yong)(yong)(yong)的(de)鋼(gang)腳手(shou)架(jia)等用(yong)(yong)(yong)鋼(gang)管(guan)(guan)(guan)制(zhi)(zhi)(zhi)造(zao)(zao)(zao)環(huan)形零件，可提高材料(Material)利用(yong)(yong)(yong)率(availability)，簡化(hua)制(zhi)(zhi)(zhi)造(zao)(zao)(zao)工(gong)(gong)序(xu)，節(jie)約材料和加工(gong)(gong)(Processing)工(gong)(gong)時，已廣泛用(yong)(yong)(yong)鋼(gang)管(guan)(guan)(guan)來制(zhi)(zhi)(zhi)造(zao)(zao)(zao)。
