10NiCrMoV铁粉焊条韧性研究

Toughness of 10NiCrMoV iron powder type electrode

针对10NiCrMoV高效铁粉焊条在研制过程中,对接接头的韧性与熔敷接头相比大幅度下降的现象进行了试验研究与原因分析。试验结果表明,由于熔敷和对接接头的焊道布置不同,导致冲击试样缺口位置的组织和成分存在差异。对接接头冲击缺口附近的组织中存在发达的柱状晶,受母材影响强化元素含量增高,这两个因素是导致韧性下降的主要原因。通过提高焊接速度从而限制焊道高度,充分利用后续焊道对前一焊道的热作用细化晶粒,可以很好地改善焊接接头的韧性。

In the development of 10Ni8CrMoV iron powder type electrode, it was found that the toughness of welded joint decreased greatly by contrast to deposited metal. In this paper, the toughness of welded joint was studied. The results showed that the microstructure and chemical compositions of welded joint were different from the deposited metal due to the different layout of weld bead. The toughness of welded joint decreased greatly because of large columnar grain and high content of strengthening elements. The toughness of welded joint can increase by improving welding speed, because the thin bead can obtain the more refined grain.