單機(jī)架減徑率對(duì)無(wú)縫鋼管周向壁厚影響的研究

A Study Concerning Effect by Single Stand Reducing Rate on Circumferential Wall Thickness Evenness of Seamless Steel Tube

摘要: 在熱軋無(wú)縫鋼管的微張力減徑工藝中，一般不會(huì)引發(fā)“內(nèi)六方”缺陷，但是厚壁管在微張力減徑時(shí)容易產(chǎn)生周向壁厚不均的質(zhì)量缺陷。通過(guò)利用ANSYS/LS-DYNA有限元軟件動(dòng)態(tài)模擬不同機(jī)架的應(yīng)力應(yīng)變狀態(tài)可以發(fā)現(xiàn)，采用微張力減徑時(shí)，鋼管的周向壁厚存在差異。在總減徑率不變的前提下，降低單機(jī)架減徑率，可以改善熱軋無(wú)縫鋼管的周向壁厚不均缺陷。

Abstract: During the slight-stretch reducing process of hot-rolled seamless steel pipes，normally，it is impossible to get the inner hexagonal defect developed. Nevertheless，in case of producing heavy-wall tubes，frequently， the slight-stretch reducing operation causes the quality defect of transversal uneven wall thickness. With employment of the ANSYS/LS-DYNA finite element（FE）software，the stress and strain statuses of different stands are dynamically simulated，which leads to identifying the fact that even in case of the pipe being slight-stretch reduced，there still exists circumferential wall thickness difference. Given that the total reduction ratio remains unchanged， decreasing the reduction ratio of the individual stand will eliminate the defect of circumferential wall thickness difference.