Are T-1 steels prequalified per AWS D1.1?

One basic premise of D1.1 is that the steel, be it a carbon steel or high strength low alloy steel, must not have a specified minimum yield strength  greater than 100 ksi. That is stated in Clause 1. If the steel is higher in strength, the Engineer must take a position on the use of the high strength steel.

The strength of the base metal is not an essential variable per Table 4.11, thus it can be increased or decreased at will without the need to requalify the welder. However, the employer still retains the responsibility to ensure the welders know and understand the complications associated with welding high strength steels. A little instruction may be in order, but I see no requirement to test the welder on the higher strength steel. 

One must remember that the welder qualification test simply allows the welder to demonstrate the minimum skills necessary to deposit a sound weld, i.e., one that is free of the defects listed in clause 4.9. AWS D1.1 doesn't not require the welder of have any knowledge of how to set the welding machine up to weld, it does not require the welder to demonstrate knowledge of the base metals being joined or a fundamental understanding of metallurgy, it does not require the welder to read and understand welding symbols, it does not require the welder to know how use a torch, carbon arc cutting equipment, grinder, understand safety, read, or write.  Should the employer expect the welder to know and understand the subjects listed in the previous sentence? That is up to each employer to assess and decide.

Best regards - Al