法门寺合十舍利塔钢骨结构负温焊接工艺

Welding Technology of Steel Structure at Negative Temperature in Palms-holding Dagoba for Famen Temple

法门寺合十舍利塔钢骨结构工程钢骨采用Q345GJC钢,施工经过冬季阶段（2007年11月-2008年2月）,由于冬季施工的负温环境会使焊接质量受到直接影响,降温速度加快使焊缝金属脆化,增加裂纹产生的可能性,控制不好会造成焊接质量的下降甚至造成安全隐患。为了保证负温下的焊接质量,组织了一次负温焊接试验。评定试件在焊接专家的见证下进行,模拟低温环境,由现场焊工施焊。通过有效的防护措施（焊前预热、焊后保温）及合理焊接工艺参数达到了焊接质量良好,焊接接头综合力学性能能够满足舍利塔钢骨结构焊接技术要求。根据试验结果制定了负温焊接工艺。在整个冬季施工过程的应用中获得了成功,经检验未发现一处裂纹。

The steel structure of plams-holding dagoba for Famen Temple is constructed with steel Q345GTC.The construction period is necessity through the winter,even from November of 2007 to February of 2008.Negative temperature of environment exerts direct influence to welding quality.If the droping speed of temperature is quick,the metal will be brittle,also,the possibility of crack produced at weld is increased.When the control technique is not proper,the welding quality will come down.Even the safety hidden danger is increased.Therefore,a welding test at negative temperature was made.Results of test indicate that the good welding quality may be obtained under the conditions of effective protection measure,such as preheating before welding and heat preservation after welding,as well as the proper welding technique and parameters.The comprehensive mechanical property of welding joints can satisfy with the welding technical demands of the steel bone structure of palms-holding dagoba for Famen Temple.On the basis of test results,the welding operating rules are planned at the winter and its use in the welding process at whole winter is successful.