Tensile Testing Grain Direction

By BenWelder Date 07-15-2008 11:02

Hey all,

does the grain direction have anything to do with the tensile strength? the specific material I am talking about is 4130 plate 1.5" thick. We are trying to get welding qualified for oilfield equipment and we have done an overlay test that requires a base metal tensile test and this is the only part of the test that failed. Minimum required is 75,000, results from testing was 73,200. Anyone have any experience in this field?

Thanks,

-Ben

By Joseph P. Kane (****)

Date 07-15-2008 16:23

It does make a considerable difference. In ASTM A-6, transverse tensile tests are required in normal course. I do not know what testing is required for AISI 4130. I did have a job where a "Z" direction tensile test (0.0505) was required.

By tom cooper (**)

Date 07-15-2008 16:40

Ben-
I work with 4130 all the time and in a normalized condition you should expect the UTS to be above 90 ksi and minimum yield of 70ksi. What spec are you working with and where are you seeing a "minimum requirement of 75,000" ? Are you sure you have 4130? On 1.5" plate, grain should not make the large difference you are seeing.

By js55

Date 07-18-2008 13:32

Well first of all, where did the tensiles fail?
You're doing an overlay. You sure you had full bonding?

By 803056

Date 07-18-2008 19:48

The long axis of the tensile test speciman, with the weld transverse to the long axis, should be parallel to the direction of rolling.

As Joe said, it does make a difference. The tensile strength is highest in the direction of rolling, reduced some what perpendicular to the direction of rolling, and about 50% less than the maximum in the through thickness direction.

Some "high quality" steels are bidirectionally rolled to improve the tensile strength in both directions of rolling.

Best regards - Al