摘要
利用普通液压机对初始直径为102mm、壁厚为4.5mm的20号热轧无缝钢管试件进行四次双向等长缩径,管坯试件上端润滑,下端不润滑。通过测量试件周向四个方向上的初始壁厚以及缩径后端部及均匀区的壁厚及外径,揭示出缩径后管坯壁厚在周向上变化不均匀的现象,给出了管坯初始壁厚偏差、润滑条件对各次缩径后管坯壁厚变化的影响以及管坯法向应变与周向应变比值的变化规律,解释了缩径中出现的管坯内壁周向起皱及管端轴向开裂等特殊现象,以利于实际生产中合理限定无缝管坯的初始壁厚偏差并对其进行正确润滑,从而得到壁厚变化较为均匀的合格制件。
Number 20 hot rolling seamless steel tubes ,whose diameter is 102mm and thickness is 4.5mm, were necked with e- qual lengths at both sides for four times on the general hydraulic press, with the upper side lubricated and the lower one not. Five tubes were picked out randomly to measure the wall thickness and the outer diameter of the primary tubes and of the uniformity parts and ends of the necked tubes at four different circumferential position. It＇ s found that the wall thickness changing isn＇ t e- ven circumferentially. The law is revealed that how primary wall thickness difference and lubrication condition affect the wall thickness changing, and how the strain rate of the normal and circumferential of the tubes distributes. The reasons why the circumferential buckle emerging at the tube inner and the axial split emerging at ends during necking process is also given. Based on the research, the seamless tubes whose wall thickness difference being limited reasonably will be selected and lubricated correctly in the necking process to obtain eligible products which have wall thickness changing more even.
出处
《现代制造工程》
CSCD
北大核心
2012年第4期84-88,共5页
Modern Manufacturing Engineering
基金
河北省自然科学基金资助项目(503299)
关键词
无缝钢管
缩径
壁厚偏差
应变比
试验研究
seamless steel tube
necking
wall thickness difference
strain rate
test research
