In 2015, Caston took a drill pipe order from a well-known horizontal directional drilling rig supplier in America. The pipes they ordered were required to meet their special construction conditions. So we imported a batch of special materials, and designed a group of technical parameters different from standard ones. According to their drawings, the length of expanded pipe section is 150mm longer than regular ones, and the wall thickness should be 3mm smaller than the common values. It is a contraction and difficulty to accomplish thickening, lengthening, and wall thickness reducing simultaneously in forging technique. The special material we use calls for high hardness requirements after heat treatment. But there are cracks appeared on the pipe surface because of the material's properties and the thin wall thickness. Before cooperating with us, this company has turned to many drill pipe suppliers and none of them is competent in offering the pipe they want.
After a period of research, Caston found a new graded forging and heating method as a replacement for the original heating technique. We adjusted the heating technique, the quenching media, the liquid proportion, the temperature, and the insulation time. Finally, the adjustment we have made was proven to realize the technical parameters and mechanical performance of drill pipe clients want. We signed a technical confidentiality agreement.