The processing route for material produced using QST technology contained within this specification has been heretofore implicit to a large degree. This ballot recommends several additional controls to be placed into the specification to insure that material thus manufactured has the same integrity regardless of any subtle differences in how the product may be made. - Paragraph 4.1 is amended to more accurately describe the quenching process. - Table 1 is amended to provide for improved weldability by lowering carbon, including a statement restricting any intentional use of boron. Also, phosphorous has been reduced for Grades 50 and 70 to agree with Grades 60 and 65, columbium increased for Grade 60 to agree with the others, and the range for total microalloy content controlled. - A supplementary requirement is added to call attention to any weldability tests that can be conducted, the mode and frequency of which would be at the discretion of the manufacturer and the purchaser. - Lastly, Appendix X.1.2 has been rewritten for clarity and improved explanation of the QST process.
Keywordshigh-strength low-alloy steel; QST; quenching and self-tempering process; steel shapes; structural shapes; structural steel;
Draft Under Development