Evaluating Material Properties of SA387 Chrome Moly
Evaluating Material Properties of SA387 Chrome Moly
(OP)
Our customer requested "Chrome Moly" plates. This is a non-code part, but machinability is important to us and the part is CrMoly for resistance to erosion (steam/water service). Allowable stress for design is not a factor and the part is not welded.
Does anyone have a SA387 Grade recommendation(s) for best selection based on the above criteria?
Does anyone have a SA387 Grade recommendation(s) for best selection based on the above criteria?





RE: Evaluating Material Properties of SA387 Chrome Moly
RE: Evaluating Material Properties of SA387 Chrome Moly
RE: Evaluating Material Properties of SA387 Chrome Moly
RE: Evaluating Material Properties of SA387 Chrome Moly
I've had a career's worth of questions caused by similarly sloppy use of the word 'stainless'.
RE: Evaluating Material Properties of SA387 Chrome Moly
The customer is concerned about Flow Accelerated Corrosion (FAC)(power generation heat exchangers). My origianl short list was Gr11, 12, and 22. I think that they should all hold up equally well for the FAC. I didn't know if another grade was far superior for this type of issue (ie Grade 5). We are drilling a significant amout of holes, so the machinability is of intrest to us. I'm not sure yield strength directly corrolates to machinability, but the Grade 22 (Cl 1) has the least yield of the three grades so I'm inclined to use that material.
Does anyone know if there is a noticable difference in machining (drilling) bewteen Grade 11, 12, 22 (Class 1 or 2)?
RE: Evaluating Material Properties of SA387 Chrome Moly
RE: Evaluating Material Properties of SA387 Chrome Moly
The mill finally got back to me and they said that there is no difference in the way the Grade 11 or 22 machine. This probably makes sense given the Sulfur content of the materials in question is the same.
We opted for Gr11 since the improvement will be significant compared to the A36 that these parts are replacing. I think the improvement that Gr 22 has over Gr 11 (for FAC) in this application is not worth the extra cost in materials.
Thanks to everyone who contributed to this post.