Cracking Analysis of high-pressure metal hoses

Chemical composition of the base metal hoses meet the standard requirements , microstructure normal . Failure hose member and the base metal and weld finished piece unused micro-cracks are present on the hose , the hose which indicates that micro-cracks before they are used . According to the position and shape of micro-cracks can be divided into two categories: one is located on the weld , the weld along the direction of the main direction of the crack , in addition to many cracks perpendicular to the main secondary cracks , these cracks are located weld intergranular columnar crystal Hydraulic tube fittings is formed when the welding weld cracking ; second crest of microcracks in the inner surface of the hose , these micro- cracks in the circumferential direction along the hose (Up direction perpendicular to the weld ). and substantially parallel to each other , since the majority of these micro-cracks exist in the inner surface of the crest , and the analyzes were performed by location and morphology with regularity , so these cracks should be rolling waves generated when processing cracks. In welding and molding process , the micro crack initiation at the inner surface of the hose in the subsequent assembly process of trial and the use of extended fatigue microcracks , finally cracked through , causing oil spills . Recommended welding hose and processing to improve, in order to avoid the generation of microcracks .