A-36 SemiKilled or Killed Material

[tgregg]

Need some help to try and prove that some 3/8" thk. A-36 plate is either SemiKilled or Killed. It is foreign material and they do not say it on the MTR's. The Domestic Mills usually put it on. How can I prove that it's not rimmed or cup material and is either SemiKilled or Killed. We have an inspector giving us a hard time. Thanks

 

[JStephen]

Contact the supplier, the mill rep, or the mill. It's possible that all the steel they produce is killed or semikilled etc, in which case a letter to that effect should suffice.

 

[JoeTank]

I've been told by metallurgists that the MTR can be reviewed and that the amount of silicon or aluminum can also be a clue as to whether it was killed or semi-killed. Sorry, but I do not recall the amounts required to achieve these conditions.

Joe Tank

 

[IFRs]

For what it's worth:

The term “killed” indicates that the steel has been sufficiently deoxidized to quiet the molten metal when poured into the ingot mold. The general practice is to use aluminum ferrosilicon or manganese as deoxidizing agents. A properly killed steel is more uniform as to analysis and is comparatively free from aging. However, for the same carbon and manganese content Killed Steel is harder than Rimmed Steel. In general all steels above 0.25% carbon are killed, also all forging grades, structural steels from 0.15% to 0.25% carbon and some special steels in the low carbon range. Most steels below 0.15% carbon are rimmed steel.

 

[metengr]

tgregg;
Remove a small section of the suspect steel and have a metallurgical lab perform a quantitative chemical analysis to show the Inspector that the steel is killed. The Si and Al contents should be reported in your analysis (provided the steel is indeed killed).