低合金钢管板管孔加工技术

Study on hole processing technology of low alloy steel tube-sheet

针对低合金钢管板的管孔加工,对比分析了目前国内常用管孔加工机具一次加工成型管孔质量的差异,试验对比了相同液压胀力下初始间隙0.36 mm和0.26 mm的10^(#)+16Mn胀接接头的密封性和拉脱力变化。指出GB/T 151—2014中对管板孔桥宽度B值随管板厚度变化的限定值已经落后,应在该标准修订时进行调整。研究发现,管孔表面粗糙度应根据换热管外表面粗糙度、管束密封性和拉脱力的设计要求进行调整,随着装备制造加工技术的提高,管板孔的加工机具应在数控钻、加工中心、数控深孔钻中进行选择,逐步淘汰摇臂钻。

In view of the hole processing of low alloy steel tube-sheet,the quality difference of tube holes formed by one time in the common tube hole processing machine in China,the changes in sealing property and pull-out force of 10^(#)+16Mn expansion joints with initial clearance of 0.36 mm and 0.26 mm under the same hydraulic expansion force were compared by tests.It is pointed out that the limit value B of the width between continuous holes with changes in the thickness of tube sheet in GB/T 151—2014 has been backward,and should be adjusted when the standard is updated.It is found that the surface roughness of the hole should be adjusted according to the outer surface roughness of the exchange tube,the design requirements for the tube bundle sealing performance and the pulling force.With the improvement of processing technology in Chinese equipment manufacturing industry,the processing machines for tube sheet holes should be selected from CNC drilling machine,machining center and CNC deep hole drilling machine,and the radial drilling machine should be phased out gradually.