平(ping)封(feng)(feng)(feng)頭(tou)的幾何形(xing)狀突(tu)變(bian)(bian)和(he)頻繁停(ting)爐是(shi)產(chan)生(sheng)裂紋的主要原(yuan)因。防焦(jiao)(jiao)箱(xiang)(xiang)直(zhi)接受(shou)火焰(yan)加熱(re)。平(ping)封(feng)(feng)(feng)頭(tou)邊(bian)緣的突(tu)變(bian)(bian)處易產(chan)生(sheng)應(ying)力集(ji)中。由于封(feng)(feng)(feng)頭(tou)底部(bu)(bu)與防焦(jiao)(jiao)箱(xiang)(xiang)壁(bi)(bi)厚不等，因此，當鍋爐在運行過程中，工(gong)作壓力將使封(feng)(feng)(feng)頭(tou)突(tu)變(bian)(bian)處相互約(yue)束，產(chan)生(sheng)應(ying)力集(ji)中。再(zai)則，防焦(jiao)(jiao)箱(xiang)(xiang)封(feng)(feng)(feng)頭(tou)裂紋區(qu)外(wai)壁(bi)(bi)所吸(xi)收的熱(re)量(liang)通過封(feng)(feng)(feng)頭(tou)內(nei)壁(bi)(bi)傳(chuan)(chuan)給防焦(jiao)(jiao)箱(xiang)(xiang)內(nei)的介(jie)質效果差(cha)。而(er)端部(bu)(bu)介(jie)質循環效果也較差(cha)。這樣(yang)也就減慢了熱(re)傳(chuan)(chuan)遞(di)速(su)度(du)，熱(re)能(neng)增大(da)，溫度(du)上升。

? 常(chang)(chang)用(yong)(yong)(yong)的(de)對焊管(guan)(guan)(guan)(guan)件(jian)包(bao)括彎頭(tou)、三通(tong)(tong)(tong)(tong)、異徑管(guan)(guan)(guan)(guan)(大小頭(tou))和管(guan)(guan)(guan)(guan)帽(mao)，項大多采(cai)用(yong)(yong)(yong)無縫鋼管(guan)(guan)(guan)(guan)或焊接(jie)(jie)鋼管(guan)(guan)(guan)(guan)通(tong)(tong)(tong)(tong)管(guan)(guan)(guan)(guan)帽(mao)價格管(guan)(guan)(guan)(guan)件(jian)及連(lian)接(jie)(jie)形(xing)式過推制、拉(la)拔、擠(ji)壓而(er)成，后者多采(cai)用(yong)(yong)(yong)鋼板沖(chong)壓而(er)成。同(tong)徑三通(tong)(tong)(tong)(tong)用(yong)(yong)(yong)于可燃(ran)氣體(ti)管(guan)(guan)(guan)(guan)道(dao)上時(shi)宜采(cai)用(yong)(yong)(yong)密封(feng)(feng)焊進行密封(feng)(feng)，同(tong)徑三通(tong)(tong)(tong)(tong)在很多情況(kuang)下，平底封(feng)(feng)頭(tou)廠，如管(guan)(guan)(guan)(guan)廊上的(de)管(guan)(guan)(guan)(guan)子端部，管(guan)(guan)(guan)(guan)帽(mao)都由法蘭代(dai)替，以便于管(guan)(guan)(guan)(guan)子的(de)吹掃和清洗。y型三通(tong)(tong)(tong)(tong)經常(chang)(chang)代(dai)替一(yi)般三通(tong)(tong)(tong)(tong)，用(yong)(yong)(yong)于輸送有固體(ti)顆粒或沖(chong)刷腐蝕較嚴重的(de)管(guan)(guan)(guan)(guan)道(dao)上。常(chang)(chang)用(yong)(yong)(yong)的(de)管(guan)(guan)(guan)(guan)件(jian)中，螺(luo)紋短節為陽螺(luo)紋，而(er)彎頭(tou)、三通(tong)(tong)(tong)(tong)、管(guan)(guan)(guan)(guan)帽(mao)、活接(jie)(jie)頭(tou)等多為陰螺(luo)紋，使(shi)用(yong)(yong)(yong)時(shi)應注意它之(zhi)間的(de)搭配和組合。螺(luo)紋連(lian)接(jie)(jie)與焊接(jie)(jie)相比，其接(jie)(jie)頭(tou)強度低，密封(feng)(feng)性能差。

對(dui)潤滑(hua)油管(guan)(guan)(guan)道當采(cai)用(yong)(yong)承插焊(han)連(lian)(lian)接(jie)時(shi)(shi)(shi)，碳鋼平底封頭價格，其接(jie)頭縫隙處(chu)易積存雜質(zhi)而(er)對(dui)機械設(she)備發生有利影響(xiang)，此(ci)時(shi)(shi)(shi)也應采(cai)用(yong)(yong)對(dui)焊(han)連(lian)(lian)接(jie);螺(luo)紋(wen)(wen)連(lian)(lian)接(jie)的(de)管(guan)(guan)(guan)件應采(cai)用(yong)(yong)錐管(guan)(guan)(guan)螺(luo)紋(wen)(wen);dn≥50管(guan)(guan)(guan)道及其元件常用(yong)(yong)的(de)一(yi)種連(lian)(lian)接(jie)型(xing)式。對(dui)于(yu)dn≤40管(guan)(guan)(guan)子及其元件，因為它壁厚一(yi)般較薄，采(cai)用(yong)(yong)對(dui)焊(han)連(lian)(lian)接(jie)時(shi)(shi)(shi)錯口影響(xiang)較大，容易燒穿，焊(han)接(jie)質(zhi)量不(bu)(bu)易保證，故(gu)此(ci)時(shi)(shi)(shi)一(yi)般不(bu)(bu)采(cai)用(yong)(yong)對(dui)焊(han)連(lian)(lian)接(jie);同時(shi)(shi)(shi)要求其彎曲半徑(jing)(jing)不(bu)(bu)宜(yi)小于(yu)其公稱(cheng)直徑(jing)(jing)的(de)1.5倍。當斜(xie)(xie)接(jie)彎頭的(de)斜(xie)(xie)接(jie)角度大于(yu)450時(shi)(shi)(shi)，螺(luo)紋(wen)(wen)連(lian)(lian)接(jie)不(bu)(bu)得用(yong)(yong)在有毒介(jie)質(zhi)管(guan)(guan)(guan)道上;焊(han)制斜(xie)(xie)彎頭：常用(yong)(yong)于(yu)介(jie)質(zhi)條件比擬緩和的(de)大尺寸管(guan)(guan)(guan)道上。不(bu)(bu)宜(yi)用(yong)(yong)于(yu)

有毒(du)、可燃(ran)介(jie)質管(guan)道(dao)上，或接受機械(xie)振動、壓力脈(mo)動及由(you)于溫(wen)度變(bian)化(hua)發生交變(bian)載(zai)荷(he)的管(guan)道(dao)上。

? 碳(tan)(tan)(tan)鋼(gang)封(feng)頭與(yu)不銹鋼(gang)封(feng)頭的(de)(de)(de)(de)生產(chan)工(gong)(gong)藝介紹： 1，在(zai)生產(chan)中有不合(he)適的(de)(de)(de)(de)地方(fang)沾到(dao)了碳(tan)(tan)(tan)鋼(gang)了。主(zhu)要是加工(gong)(gong)硬(ying)化性造(zao)成的(de)(de)(de)(de)，沖壓(ya)時(shi)的(de)(de)(de)(de)變形(xing)(xing)使不銹鋼(gang)產(chan)生了變形(xing)(xing)馬氏體(ti)，產(chan)生磁性 。每(mei)一(yi)種解釋其(qi)實都(dou)很合(he)理。 這種現(xian)(xian)象受到(dao)冷(leng)卻(que)(que)速(su)度(du)(du)，材料成分和熱處理工(gong)(gong)藝等因素的(de)(de)(de)(de)影響(xiang)。當冷(leng)卻(que)(que)速(su)度(du)(du)愈快，含碳(tan)(tan)(tan)量和合(he)金成分愈高(gao)，平底封(feng)頭，冷(leng)卻(que)(que)過程(cheng)中在(zai)熱應(ying)(ying)力(li)(li)(li)(li)作用下產(chan)生的(de)(de)(de)(de)不均勻塑性變形(xing)(xing)愈大(da)，后形(xing)(xing)成的(de)(de)(de)(de)殘(can)余應(ying)(ying)力(li)(li)(li)(li)就(jiu)愈大(da)。 另一(yi)方(fang)面鋼(gang)在(zai)熱處理過程(cheng)中由于組織的(de)(de)(de)(de)變化即(ji)奧氏體(ti)向馬氏體(ti)轉變時(shi)，因比容(rong)的(de)(de)(de)(de)增大(da)會(hui)伴隨工(gong)(gong)件體(ti)積的(de)(de)(de)(de)膨(peng)脹，工(gong)(gong)件各部(bu)位先后相變，造(zao)成體(ti)積長大(da)不一(yi)致而產(chan)生組織應(ying)(ying)力(li)(li)(li)(li)。不銹鋼(gang)封(feng)頭組織應(ying)(ying)力(li)(li)(li)(li)變化的(de)(de)(de)(de)終結果是表層受拉應(ying)(ying)力(li)(li)(li)(li)，心(xin)部(bu)受壓(ya)應(ying)(ying)力(li)(li)(li)(li)，恰好與(yu)熱應(ying)(ying)力(li)(li)(li)(li)相反(fan)。組織應(ying)(ying)力(li)(li)(li)(li)的(de)(de)(de)(de)大(da)小與(yu)工(gong)(gong)件在(zai)馬氏體(ti)相變區的(de)(de)(de)(de)冷(leng)卻(que)(que)速(su)度(du)(du)、形(xing)(xing)狀，材料的(de)(de)(de)(de)化學成分等因素有關，我公(gong)司現(xian)(xian)所有的(de)(de)(de)(de)產(chan)品(pin)都(dou)以格出售? 全部(bu)，人家都(dou)了我公(gong)司也出售。