The requirements for materials and their strength significantly increased with the new generation of coal fired power plants operating at steam temperatures of up to 620 °C. Therefore, new materials were introduced to fulfill the defined needs. During the commissioning process of the first plant many cracks occurred in welds of T24 material. The cracks showed clear characteristics of stress corrosion cracking (SCC). Not knowing the exact parameters that lead to cracking, experiments in high temperature water were carried out. Slow tensile tests in a controlled environment are extremely well suited to generate information about material's SCC sensitivity. In the present paper, the influence of the temperature, the oxygen concentration of water, the pre-treatment of the specimen and the heat treatment to the SCC are investigated. Furthermore critical limits for the cracking are defined where possible.

随着新一代燃煤发电厂在高达620°C的蒸汽温度下运行，对材料及其强度的要求大大提高。因此，引入了新材料以满足定义的需求。在第一家工厂的调试过程中，T24材料的焊缝中发生了许多裂纹。裂纹表现出明显的应力腐蚀裂纹（SCC）特征。由于不知道导致破裂的确切参数，因此在高温水中进行了实验。在受控环境中进行缓慢的拉伸测试非常适合生成有关材料的SCC敏感性的信息。本文研究了温度，水中氧气浓度，试样的预处理和热处理对SCC的影响。