| 摘要 |
The present invention relates to a friction welded product for rock drilling, including a first component (25) and a second component (22) of parent material joined by a friction weld (27). The components have a central inner passage (26). Each component (22, 25) is heat treated at low temperature and is made from a steel having a chemical composition such that the core hardness after nitrocarburizing of the component (22, 25) is at least 440 HV1. The core hardness of the most tempered parts of the heat affected zone close to the weld (27) is about the same as for the core hardness of the rod when cooled to room temperature of at least 390 HV1. The first component (25) comprises a threaded portion (11) and a clearance portion (12) which are pretreated against corrosion fatigue preferably by nitrocarburizing the first component (25) separately and then friction welding it to the second component (22), such as a rod (13). The present invention further relates to a method for manufacturing a friction welded drill rod for rock drilling. |
