厚壁鋼管不(bu)均主(zhu)要體現的三(san)個方(fang)面

　　厚壁鋼管不均(jun)主(zhu)要體現為螺(luo)旋狀(zhuang)壁不均(jun)、直線狀(zhuang)壁厚(hou)不均(jun)及頭尾(wei)部壁厚(hou)偏厚(hou)、偏薄等現象

　　一、螺旋狀厚壁鋼管不(bu)均(jun)的成(cheng)因(yin)是(shi)穿孔機軋(ya)制中(zhong)心(xin)線不(bu)正、兩軋(ya)輥的傾(qing)角不(bu)等或頂頭前壓下量太小(xiao)等調(diao)(diao)整原因(yin)造成(cheng)的壁厚(hou)不(bu)均(jun)，一般沿鋼管(guan)的全長呈螺(luo)旋(xuan)狀(zhuang)分布。主(zhu)要措施是(shi)調(diao)(diao)整穿孔機軋(ya)制中(zhong)心(xin)線，使兩軋(ya)輥的傾(qing)角相等，按軋(ya)制表給定參數(shu)調(diao)(diao)整軋(ya)管(guan)機。

　　二、直線狀壁厚不(bu)均的原因是(shi)芯(xin)棒(bang)(bang)預(yu)穿(chuan)鞍座高度調整(zheng)(zheng)不(bu)合(he)適，芯(xin)棒(bang)(bang)預(yu)穿(chuan)時接觸(chu)到某(mou)一(yi)面(mian)的毛管(guan)(guan)(guan)，致使毛管(guan)(guan)(guan)在接觸(chu)面(mian)上(shang)溫降過快(kuai)，造成(cheng)壁厚不(bu)均甚至(zhi)拉凹缺陷。連軋(ya)(ya)(ya)(ya)軋(ya)(ya)(ya)(ya)輥(gun)間隙(xi)過小或(huo)過大(da)。　軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)機(ji)中(zhong)心線偏差(cha)。單(dan)、雙(shuang)(shuang)機(ji)架(jia)壓下量不(bu)均，會造成(cheng)鋼管(guan)(guan)(guan)單(dan)機(ji)架(jia)方向超薄(超厚)、雙(shuang)(shuang)機(ji)架(jia)方向超厚(超薄)的直線型對(dui)稱偏差(cha)。主要(yao)措施是(shi)調整(zheng)(zheng)好芯(xin)棒(bang)(bang)預(yu)穿(chuan)鞍座的高度、保證芯(xin)棒(bang)(bang)與(yu)毛管(guan)(guan)(guan)對(dui)中(zhong)。更(geng)換孔型及軋(ya)(ya)(ya)(ya)制(zhi)規格時應測量軋(ya)(ya)(ya)(ya)輥(gun)間隙(xi)，使實(shi)際軋(ya)(ya)(ya)(ya)輥(gun)間隙(xi)與(yu)軋(ya)(ya)(ya)(ya)制(zhi)表保持一(yi)致。用光學(xue)對(dui)中(zhong)裝(zhuang)置調整(zheng)(zheng)軋(ya)(ya)(ya)(ya)制(zhi)中(zhong)心線，年度大(da)修時必須(xu)校正軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)機(ji)中(zhong)心線。

　　三頭、尾(wei)部壁(bi)厚不(bu)均的原因是(shi)管(guan)坯前(qian)端切(qie)斜度(du)(du)、彎曲度(du)(du)過大、管(guan)坯定(ding)(ding)心(xin)(xin)孔不(bu)正易(yi)造成鋼(gang)管(guan)頭部壁(bi)厚不(bu)均。穿孔時(shi)延(yan)伸系(xi)數(shu)太(tai)(tai)大、軋(ya)輥(gun)轉速(su)太(tai)(tai)高(gao)、軋(ya)制(zhi)不(bu)穩(wen)定(ding)(ding)。穿孔機拋鋼(gang)不(bu)穩(wen)定(ding)(ding)易(yi)造成毛管(guan)尾(wei)部壁(bi)厚不(bu)均。措(cuo)施(shi)是(shi)檢(jian)(jian)查管(guan)坯質量(liang)，防止(zhi)管(guan)坯前(qian)端切(qie)斜度(du)(du)、壓下(xia)量(liang)大，更換孔型或檢(jian)(jian)修均應(ying)校正定(ding)(ding)心(xin)(xin)孔。采(cai)用較(jiao)低的穿孔速(su)度(du)(du)，以確保軋(ya)制(zhi)的穩(wen)定(ding)(ding)性和毛管(guan)壁(bi)厚的均勻度(du)(du)。當(dang)軋(ya)輥(gun)轉速(su)調整后，匹(pi)配的導(dao)盤也做相應(ying)調整。