高频生产线预焊合缝装置挤压保持距离的设计

Design of Pre-welding/Weld-joining Device's Extrusion-holding Distance of HF Weld Pipe Production Line

气体保护预焊接后钢管需要保持挤压状态运行一段距离,以保证钢管预焊接后有足够强度克服弹复力作用。介绍了高频生产线预焊接后钢管保持挤压状态运行距离的设计方法。通过对焊接钢管离开自保持段后焊缝的受力情况进行分析,推算出焊缝冷却温度及所需时间,最后确定出预焊合缝装置挤压保持距离。合理的挤压保持距离,既可保证焊缝冷却到有足够强度克服弹复力作用,又不会因为挤压距离过长而造成挤压力过大,出现错边时挤压辊无法压下的问题。

After being shielded arc welded, the steel pipe as in the extrusion state has to be running for a speci- fic distance so as to ensure that the pre-welded tube has enough strength against the elastic force effect. Elaborated in the article is the method for making design for this purpose. Based on the analysis of the weld stress state of the tube that has run through the self-holding distance, the weld＇ s cooling temperature and time are deduced, and then the said extrusion distance held by the pre-welding/weld joining device is determined. As the said distance is properly specified and held, the weld can be cooled down to a certain extent to have sufficient strength against the elastic force effect, while it is possible to avoid the troubles like weld offsetting or the extrusion roll＇s failure to be pressed down due to the over large extrusion force as caused by the over-long extrusion distance.