Comparison of Scrap Charged to Pig Iron Based Steel

[natebott]

Has anyone noticed a difference in performance of steels manufactured from scrap steel as opposed to the traditional method involving pig iron? We have end users of our products saying that the steel is not as good as it used to be. We use more scrap based steel than before, so is there a difference, or is this the case of jumping on the "bad steel" bandwagon.

Also, if you have seen any good articles on this topic please inform me where.
Thanks.

 

[Maui]

The vast majority of tool steel and high speed steel that is currently manufactured throughout the world for industrial applications is made primarily from scrap. I would be hard pressed to identify even one commercial source that produces their products from 100% virgin ores. What particular grade of steel are you referring to? What is the application and what specifically is your customer complaining about?

Maui

 

[natebott]

Mostly A36 hr plate and some shafting bar stock (4140, 4150). We manufacture wood recycling equipment. The comments from end users are general, things like "Steel just isn't as good as it used to be".

 

[arunmrao]

Secondary production of steel is a very important economic activity and is widely accepted.

It is not possible to use always pig iron for steel making.

Your customer's comments are similarly echoed by some casting users as follows"Castiron castings made from cupola metal are better than those similarly produced by induction melting"

 

[EdStainless]

No, it isn't what it used to be. Thank Goodness.
Chemistry control is much better today, and general steel practice is much more consistent.
The amount of some tramp elements is creaping up (such as Cu). And some important (and expensive) additions are trimmed as low as specs allow.
The same rules as always apply though; 'you don't always get what you pay for, but you never get more than you pay for'.



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[swall]

Electric furnace melted steel, from scrap, can be very high quality steel, such as special bar quality for axle shafts, etc. The only advantage (at least to the end user) for steel made from iron ore via the blast furnace and BOF route is the low level of residuals obtained. This is extremely important for cold rolled sheet, such as drawing quality used for auto body stampings.

 

[stanweld]

Without a definition of what is not "good" about the steels which your firm purchases, little useful feedback can be given. With the advent of continuous casting, the percentage of hot working may be reduced and the homogeneity of some of your purchased products may be somewhat inferior. You also may be purchasing from the lowest cost suppliers (bean counters over engineers)who may not be providing the quality actually needed; heed Ed's comments in that regard. In general steels are made with superior quality than when I began in basic steel making 38 years ago.

 

[YYS]

Scrap steel has different quality levels. What type of scrap steel is used makes difference in the qulaity of the final steel product. With low quality scrap steel as raw material, the steel refining will be more difficult and if the refining process is not well controlled to reach chemistry and cleanliness targets, it will be inferior to the steel made with virgin iron ingots.