Everyone likes a little ass, but no one likes  smart ass! 

Best regards - Al

Hello John;

The point I was trying to make is that there may be no requirement to use AWS D1.1.

Different welding standards are available that may better address the needs of this individual.

ASTM A514 is a quenched and tempered steel. The welding technique used should consider the heat input and the possibility that utilizing the wrong welding technique could degrade the properties of the HAZ such that the optimum properties may not be achieved.

Normally the purpose of the welder performance test is to verify the welder can deposit a sound weld. The goal isn't to verify the procedure used is capable of producing the required mechanical properties. That being the case, certain welding standards allow the welder to weld base metals that are not necessarily the same as that used in production. However, in this case there is no requirement for the employer to meet the requirements of a specific welding code or standard.

My personal philosophy and preference is for the welder use the same base metal and the same technique (procedure) as will be used in production to ensure the welder understands what he is expected to do. Since there may be no mandatory code requirement, the company may decide not to qualify the welding procedure as outlined in AWS D1.1, ASME Section IX, or AWS B2.1. They may opt to simply have each welder weld a coupon and utilize a guided bend test to assess the ductility and soundness of the weld.

If the company elected to evaluate the welded test coupons by radiography, they would not know whether the welded had sufficient ductility. While the guided bend test doesn't provide the same information the reduced section tensile test does, it does provide some information such as whether sufficient preheat is used to avoid a hardened HAZ, whether delayed cracking is a problem (the guided bends would fail if there were preexisting hydrogen cracks in the HAZ), and whether the HAZ was grossly degraded indicated when the bends are concentrated in the HAZ  when a plunger and die bending machine was utilized.

Quenched and tempered steels typically have less ductility than lower strength steels. It is back to basics; higher strength, higher hardness, at the expense of ductility. The fact that a welded sample of Q&T steel was successfully bent using a smaller than recommended mandrel diameter is an indication that the HAZ cooled too slowly, i.e., excessive heat input, which translates into a potential for lower toughness, lower strength, lower hardness, greater ductility. In other words, you lost some of the mechanical properties that you paid a premium to get because the heat input wasn't properly monitored.

While I am not saying there is a linear correlation between the ratios of TS/YS, it does provide a reasonable comparison of the ductility of two different steels. Consider ASTM A36. The ratio of TS/YS is approximately 58/36 = 1.6. The TS/YS ratio for ASTM A514 is approximately 100/90 = 1.1. Published mechanical properties list the ductility of A36 to be about 20-22% minimum in 2 inches while A514 is about 16%-18% minimum. As the ratio of TS/YS approaches unity, lower ductility can be expected when compared to a steel that has a ratio greater than 1.

Perhaps I am straying from the question asked in the original post, so I’ll stop here.

Best regards – Al

In these aplications the "stronger" materials are being used for their greater wear resistance rather than their greater strength, aren't they?

Always wanted to read a copy of D14.3. I worked in one shop that was an ESCO and Caterpillar authorized manufacturer and all our work was fabbed to D1.1 criteria. Also, E71T-1 was the primary filler. I know of one Marion Dragline (100 plus cubic yard) that was built with Lincoln NR211!
Consistent and proper preheat is extremely difficult with these type assemblies due to size, geometry, ambient temp, weather and other conditions. Weed burners are the heat source of choice and as a welder in the maintenance of these, cracking was a common occurrence. Foremen would just tell you to keep adding weld till the piece wouldn't fall off. During hardfacing overlay and damming/lacing, there are no crack free welds... well very few.