我厂最近生产某产品中有一批Cr25 Ni20钢管需焊接,管子焊缝要求100%X光透视,同时只准单面焊接,不允许管内加垫环,其理由是内径不能减少,不许有沉积物料的现象。管子工作温度1030℃,规格φ120×12,由于管子要求较高,因此在生产中曾一度造成困难。开始我们采用手工电弧焊,焊条选用254E和0KR7一类的25—20型焊条,但经拍 I recently produced a plant in a number of products need to be welded Cr25 Ni20 pipe, pipe welding requires 100% X-ray, while only one-sided welding, pipe is not allowed to add the ring, the reason that the diameter can not be reduced, the deposition of materials are not allowed The phenomenon. Tube temperature 1030 ℃, size φ120 × 12, due to higher requirements of the pipe, so once in production caused difficulties. Beginning we use manual arc welding, electrode selection 254E and 0KR7 type 25-20 electrode, but after the beat