15CrMo合金板具有一定的抗氢腐蚀性能
The metal structure of15CrMo合金钢板是马氏体，在650摄氏度左右具有良好的抗氧化性，在600摄氏度以下具有良好的热强度，并且具有良好的减震性和导热性。广泛应用于汽轮机中。然而，15CrMo板材有很大的硬化倾向，焊接性较差。可轧制5-70MM厚的15CrMo钢板。
Features of15CrMo钢板材：具有良好的抗氧化性、耐腐蚀性和织构稳定性。热强度高，工艺性能好。
15CrMo alloy plate is a pearlitic heat-resistant steel with high heat strength (δb≥440MPa) and oxidation resistance at high temperature, and has certain resistance to hydrogen corrosion. Due to the high content of Cr, C and other alloying elements in the steel, the hardening tendency of the steel is obvious and the weldability is poor.
Therefore, the preheating temperature was selected to be 150 °C. The test piece is heated by the oxygen-acetylene flame. Firstly, the temperature of the surface of the test piece is roughly judged by the temperature measuring pen (estimated by the change of the color of the handwriting), and finally measured by a semiconductor thermometer, and at least three points should be selected for the measurement point. In order to ensure that the test piece as a whole meets the required preheating temperature.
15CrMo Alloy Plate Welding
When welding, the first layer is made by manual tungsten argon arc welding. In order to avoid the depression on the back side of the weld at the back weld, the inner wire is used for wire feeding, that is, the wire is fed from the pipe through the gap. The remaining layers are welded by electrode arc welding, and 6 layers are welded together, one weld bead per weld layer.
It is feasible to use two welding schemes for the welding of 15CrMo steel thick-walled high-pressure pipes. In order to ensure that the weld bead performance is matched with the base metal and has high heat strength, the effect of the scheme I is better, and the key is to strictly control the post-weld heat treatment process.
Although the post-weld heat treatment can be omitted, the possibility of weld migration at the high temperature and the weld seam is not negligible, so it can only be used cautiously after heat treatment after welding.
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