Titanium-based alloys with excellent corrosion resistance, widely used in petroleum, chemical, energy, environmental protection, and other industries, for the manufacture of corrosive substances in the pipeline and storage tanks, titanium elbows as a connection between these pipelines and storage tanks as a key component, its molding process has attracted much attention. The cold push-bend molding process has become one of the more advantageous elbow molding processes by virtue of high production efficiency, high material utilization, good mechanical properties of the product, simple mold structure, and other advantages. This study focuses on C276 titanium-based alloy, from the perspective of improving the cold forming properties of the material, to explore ways to improve the performance of C276 tubular billet cold push bending heat treatment process, through different heat treatment process parameters to deal with tubular billet, testing and comparing its performance, to obtain a better cold push bending preparation heat treatment process parameters.
Titanium-based alloys with excellent corrosion resistance, in the petroleum, chemical, energy, environmental protection, and many other industries, play an important role, often used in the manufacture of pipelines and storage tanks to transport corrosive substances. Titanium elbow, as a connection between these pipelines and storage tanks,is an important part of its molding quality is directly related to the safety of the entire system and stable operation.
First, in the existing elbow molding process, the cold push-bend molding process shows several advantages, such as high production efficiency, high material utilization, good mechanical properties of the product, as well as the mold structure is simple, and so on, so it has become a more advantageous elbow molding process. However, there are some problems in the process of titanium alloy elbow cold push bending, such as cold push bending cracking and other situations, which affect the quality of the product and production efficiency. This study takes C276 titanium-based alloy as the research object, aiming to explore the heat treatment process to improve its cold push-bending performance, to provide theoretical support and technical guidance for the cold push-bending molding of titanium elbows.
Second, the research content and results
(A) C276 alloy cold push bending cracking reason analysis
For the titanium elbow cold push bending process cracking, we examined the elbow microstructure, phase composition, and other factors. It was found that the grain boundary segregates present in the pipe fittings would form microcracks when subjected to tensile forces, which is the main cause of cracking in titanium elbows. This finding provides an important theoretical basis for the subsequent improvement of the cold push bending process, and only by solving the problem of grain boundary segregation can the risk of cold push bending cracking be effectively reduced.
(B) The impact of different heat treatment process parameters on the performance of C276 alloy
In order to improve the cold push bending performance of C276 alloy, we use different heat treatment process parameters for its heat treatment, and the microstructure and mechanical properties of the treated alloy were studied in detail. After a large number of experiments and comparative analysis, the better heat treatment process route was determined as: 1120℃×30 minutes + 850℃×30 minutes. After the heat treatment process, the elongation of the material reached 66%, the yield strength of 348MPa, indicating that the material's plastic forming properties are better, for the subsequent cold push-bending molding provides a good material base.
(C) The effect of different push-bending speeds on the C276 alloy cold push-bending
C276 alloy heat-treated cold push-bending experiment using different push-bending speeds. Experimental results show that after heat treatment of the billet in the push-bending process, there was no cracking phenomenon, indicating that the heat treatment process effectively improves the cold push-bending performance of the material. At the same time, in the 4mm / s push-bending speed, the C276 alloy wall thickness reduction rate of 7.5%, significantly higher than other push-bending speed samples under the wall thickness reduction rate. This result provides a reference for choosing the appropriate push-bending speed in actual production, which helps to improve the molding quality and production efficiency.
Third, the conclusion
By using the preparatory heat treatment process route and parameters (1120 ℃ × 30 minutes + 850 ℃ × 30 minutes) obtained in this paper, the C276 tubular billet heat treatment, and then cold push-bending experiments, the results show that the titanium elbow has no cracking phenomenon. This shows that the identified heat treatment process route and parameters can effectively improve the cold push-bending performance of C276 titanium-based alloy, providing a feasible technical solution for the cold push-bending molding process of titanium elbows, which has a certain practical application value. In the future, we will further study and optimize the process parameters to improve the forming quality and production efficiency of titanium elbows and promote the wider application of titanium-based alloys in related industries.
