核电厂反应堆压力容器接管与安全端焊接工艺

Summary on welding procedures of nozzle of reactor pressure vessel and its safe end in nuclear power station

核电厂反应堆压力容器接管与安全端的异种金属焊接一直都是压力容器制造过程中的重点和难点,按所选焊接材料不同,焊接工艺大致分为两大类:一种是采用不锈钢材料进行焊接;另一种是采用镍基合金材料进行焊接。当前国内在制造的反应堆压力容器的接管安全端焊缝大多数都采用不锈钢材料进行焊接,焊接结构基本都是隔离层+对接焊缝的形式。采用镍基合金焊接相比采用不锈钢焊接材料更具有优势,焊接结构大体分为两种:有隔离层和无隔离层。两类焊接材料的各种焊接工艺有各自的优缺点,都可以满足要求。

Welding of the dissimilar metal weld between the nozzle of reactor pressure vessel and its safe end is always important and difficult in the whole manufacturing process of reactor pressure vessel.According to the different types of filler materials,the welding procedures can be classified to two kinds:one is welding with stainless steel filler metal,and the other is welding with Ni based alloy filler metal.For the reactor pressure vessels be fabricated,the welds between the nozzles and the safe ends are almost welded with stainless steel filler metal,whose structure is but weld based on the isolation layer.Welding with Ni based alloy filler metal has more advantages than that with stainless steel filler metal,its joint has two types of the butt joint with and without the isolation layer.All kinds of the welding procedures with two types of filler metals are qualified,which have different advantages and disadvantages respectively.