HRPO - Hot Rolled Pickled and Oiled HSLA Steel

[roberthathaway]

I have always been under the assumption that HRPO defined a hot rolled product whose surface was completely free of mill scale in preparation for painting. We have been discovering that internationally this may not be the case. We received some Domex that was reportedly HRPO and it was dry, shinny, and looked free of scale, but upon closer examination found that it had a blue tint to it and that under SEM some areas had mill scale pulled off but the majority of the surface retained a mill scale.

Nationally/Internationally what does HRPO mean, and if I order HRPO nationally can I expect it to be free of mill scale?

Are there industry standards nationally/internationally that define HRPO and perhaps different grades or classes of pickling? A timely reply to this question would be greatly appreciated. Thank you.

 

[berkshire]

An excerpt from a supplier’s website:

Steel Products website! Hot Rolled, Pickled & Oiled
Hot Rolled Pickled and Oiled – hot rolled coil or sheet steel that has been decaled of oxide film by either a chemical method, mechanical method, or a combination of both and oiled to help retard corrosion during storage and after decaling. “HRPO” is available in various gauges, widths, and cut lengths or coil.

Based on this they are not necessarily going to get all of the oxide off.

B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor