Method for treating continuous extended lengths of tubular member interiors

In a chemical vapour deposition method for treating an interior surface of a ferrous tubular member to provide wear, abrasion and corrosion resistance to the interior surface, comprising:

• a) providing a pack composition including boron, a silicon material, an activator and diffusible carbon;
• b) exposing said interior surface to said pack composition;
• c) heating said pack composition to a temperature where at least one carburized, boronized and siliconized layer is formed on said interior surface by chemical vapour deposition and where said pack composition adheres;
• d) cooling said adhered pack composition;
• and
• e) removing said adhered pack composition from said tubular member by breaking up said adhered pack composition, the improvement for treating continuous extended lengths of tubular member interior comprising;
• f) providing a non-sintering, non-adhering, free-flowing powder pack composition, comprising:
• i) between about 5% and about 20% by weight of a suitable source of boron;
• ii) between about 2% and about 10% by weight of silicon material;
• iii) between about 2% and about 15% by weight of an activator;
• and
• iv) between about 70% and about 90% by weight of a non-sintering, non-adhering filler selected from the group consisting of non-sintering carbon and non-sintering organic compounds;
• wherein said powder pack composition is substantially free of diffusible carbon thereby minimizing carburization of said interior surface of said tubular member in the presence of the selected carbon based filler, and said powder pack composition is substantially non-sintering and non-adhering thereby remaining free-flowing after said heating and cooling steps, such free-flowing pack composition permitting the treatment of continuous lengths of said interior surface of said tubular member whereby said pack composition flows from said tubular member interior after said treatment.