整体炉外热处理法对移动烟罩实施消应力退火

为了解决武钢三炼钢厂烟罩这类大型构件不便于在常规热处理炉内进行热处理的难题，根据有关工艺和标准要求对烟罩实施了整体炉外热处理，施工中采用在烟罩中段外部包扎保温材料，同时在烟罩两端搭设简易炉体的方法对烟罩进行保温，并制定相应的热处理施工工艺，对工件进行消除应力退火。退火后进行的应力测试表明，应用此种退火技术，工件的焊接残余应力的下降率可以达到60％以上，完全可以满足大型工件的消应力退火要求。

Implementation of Stress Relief to Movable Fume Hood by Off-Furnace Heat Treatment

To solve the problem that the large size structural components are very difficult to be conventionally heat treated such as the fume hood in the No.3 Steel Plant of WISCO the heat treatment on the whole fume hood outside the furnace has been adopted according to the relative process standards and specifications. In the process of construction the construction method adopted is to bind the outside of the middle section of the fume hood with the insulating material and to build a simplified furnace body at both ends of the fume hood and to carry out stress relief treatment on working pieces. The stress measurement after annealing shows that by application of this annealing technology the welding residual stress of the working pieces can be cut down by more than 60?%and as the results the requirements of stress relief annealing for the large size working piece can basically be met.