Nitrogenous Porosity and Ways to Prevent it Under Conditions of Arc Surfacing in a Nitrogen-containing Atmosphere

Abstract

Pores coming to the surface can cause a violation of the tightness of the valve when the valve is closed, as well as be a focus of erosive destruction, especially in conditions of high-speed flows of the medium. Pores also contribute to the corrosive destruction of metals, since under the influence of certain aggressive media, they increase in size and cause a breach of the tightness of the gate. In the presence of carbon dioxide, nitrogen absorption by the weld pool metal increases and the tendency of the deposited metal to form pores decreases. The introduction of carbon dioxide of at least 30% to nitrogen makes it possible to obtain a dense deposited metal due to its better absorption of nitrogen. A significant factor reducing the formation of pores from nitrogen in the deposited metal 10X17H8X5G2T is the content of ferrotitane in the charge of the PP-AN 133 powder wire. The titanium content in the deposited metal should be within 0.2...0.4%. A further increase in the concentration of titanium leads to a deterioration in the formation of the deposited metal and to an increase in the amount of slag on the surface of the deposited layer