Is SA 179 Killed Steel

[roniprabowo]

Dear all,
Is SA 179 killed steel ? And if it is not, is there any possibilities to change it to killed steel ?

thank a lot

 

[ijzer]

SA 179 is not killed.
It can be ordered killed.

 

[steelmaking]

This steel is killed. You can not cast on CCM if it is not killed. Minimum Al content must be 0.02%. Similar steel is SAE 1010.

 

[bmoorthy]

This is indeed quite interesting i had a similar situation. Killed steel is generally a mandatory requirement for NACE applications. We had a welded tube to tube sheet joint. When i checked whether A 179 is killed or not , it did not specify clearly whether the steel is killed or not. I guess it is not correct to extend the requirement of killed steel to all product form. Some of the buyers tend to do this by giving very general statemet in their spec sheet by specifying all wetted parts shall be KILLED steel. By the way is SA 193 B 7 m a killed steel?

 

[stanweld]

bmoorthy,
A-193 B7 is "killed" steel, fully deoxidized with Silicon. Regarding A-179 it need not be "killed"; however, if the original billets were continuously cast, as steelmaking stated, the tubes will have been fully deoxidized or "killed".

 

[jackpot]

Continuously cast steel does not have to be fully killed to be cast. As a matter of fact many casters prefer to cast semi-killed products as they do not clog (inclusion build-up). Semi-killed grades like AISI 1215 with about 50 PPM of active O2 are commonly cast on continuous casters. The level of O2 activity is dependant upon the element used to kill the steel. Obviously Al will bring the active O2 level below ~10 PPM and Si will be higher. If you really want your steel killed request a 0.01% Al minimum.

Jackpot

 

[bmoorthy]

What about A194 2HM is it killed steel. Does the standard specify so. Actually the situation is like this, some of the purchase specifications gives sweeping requirement such as this " All material in contact with fluid shall be killed steel". Under such circumstances we have problem.

 

[metengr]

bmoorthy;
The chemical composition requirements for ASTM A 194 Grade 2H nuts specify a maximum of 0.4% Si, in accordance with Table 1. Fully killed steels usually contain 0.15% to 0.30% silicon - as long as silicon is not considered an alloying agent.

Review your CMTR's of the Grade 2H nuts to check for silicon content. CMTR's should be provided in accordance with 13.1 of ASTM A 194.