Factors Affecting the Low Temperature Impact Toughness of Structural Steels

结构钢在石油、能源、制造和采矿工业中有许多用途。人们对这些钢材在低温下的可靠性有一些担忧。这是由于众所周知的低温韧性-脆性转变(DBT)现象。Steel Image Inc.的内部工作清楚地表明，评估一种钢在低温应用中的适用性的传统公式不能涵盖所有重要的变量。因此，即使根据目前的标准，钢被认为是可接受的，也存在失败的风险。这项工作的目标是利用麦克马斯特大学的先进表征能力来了解控制符合ASTM A36标准的结构钢冲击韧性的因素。除了机械测试外，还将使用光学金相(OM)、透射电子显微镜(TEM)和原子探针层析(APT)来表征所有相关长度尺度上的微观结构。该项目的预期结果将使Steel Image Inc.能够为其客户提供改进的指南，以确保低碳结构钢的冷温可靠性。这将降低可能危及生命、基础设施和环境的事故风险。此外，该项目的成功将使行业伙伴能够在工艺和热处理开发领域取得增长，从而创造新的就业机会。

Structural steels are used for numerous applications in the petroleum, energy, manufacturing and mining industries. There are some concerns with the reliability of these steels at cold temperatures. This is due to the well-known phenomenon of Ductile to Brittle Transition (DBT) at low temperatures. Internal work at Steel Image Inc. has clearly demonstrated that traditional equations for assessing a steel's suitability for low temperature applications do not capture all of the important variables. As such, there is a risk of failure even when the steel is deemed acceptable according to the present standards. The goal of this work is to utilize advanced characterization capabilities at McMaster University to understand the factors that control the impact toughness of structural steels meeting ASTM A36. In addition to mechanical testing, Optical Metallography (OM), Transmission Electron Microscopy (TEM) and Atom Probe Tomography (APT) will be utilized to characterize the microstructure at all the relevant length-scales. The anticipated findings of this project will allow Steel Image Inc. to provide its clients with improved guidelines to ensure cold temperature reliability of low carbon structural steels. This will reduce the risk of accidents that could put lives, infrastructure and the environment at risk. In addition, the success of this project would allow the industry partner to grow in the area of process and heat-treatment development leading to new opportunities for job-creation.