impact testing - material equivalency between plate & pipe

[timsch]

I am preparing drawings for charpy impact testing samples and have a question about what is the correct ASTM spec to call out for the plate.

The product to be shipped to the customer has 1" SA-312 316/316L pipe that is to be welded to SA-105 socket weld fittings, designed to ASME B31.3. The customer requests that we have impact tests done for the weld procedure to be used on these welds.

The charpy impact samples are to be cut from a plate that is to be made by welding a 3/8? thick section of 316 plate with another similar plate made from CS. I am having difficulty determining what plate specs are the correct ones to call out.

I've been looking in ASME B31.3 as well as 2008a Section II, part A but have yet to have a moment of clarity.

Any pointers will be much appreciated.

 

[jwhit]

ASME Sec. IX should give you the answers you need. Look at QW422 and determine your P No.'s, any of those materials in the correct P No./Group No.(probably P1 & P8) would be acceptable. Your procedure should also be written to ASME IX and supplemented by requirements of B31.3.

 

[timsch]

Matching P-no's is easy enough. Given how many variations there are on some types of steel, I couldn't help but think that I needed to dig deeper than just the P#.

For example, CS plates can be found in SA-283, -285 & -299. All are P-1, group 1 materials, but each have been spec'd out for different purposes, which while I can read the descriptions and understand the general use for which they are intended, chemical compositions, etc., I don't always understand the deeper differences with a background of mechanical engineering rather than one of materials engineering.

 

[jwhit]

I try to qualify with the same specific material or closest chemistry and mechanicals match within the P No. & Group. Base material should have similar impact properties to what is required by the code. Since you are doing impacts the Supplementaries in QW25X will also come into play. Also, you will probably need to do both HAZ's even though the 316L will be far tougher than the carbon steel.

 

[metengr]

Why don't you order stainless steel pipe for machining CVN specimens? This is much easier and faster.

 

[timsch]

Metengr, thanks for the recommendation. That is the way that I will proceed. I realized that this was possible a couple of hours ago, but don't regret looking into it as I had up to that point as this was a good exercise for me to get a deeper understanding of the material specs.

 

[weldstan]

What is the impact test temp? If -50F purchase SA-516-70 with absorbed energy (impact toughness) > 20 ft-lbs. SA-105 will not meet -50F requirements. 316L is exempt from impat testing as would be ER309 filler metal at temps below -50F.