Scrap segregation

To ensure the best quality of finished goods,we have to melt proper scraps of desired chemichal composition,to do this scrap segration is a very important step.We have a very active and  team who are involving to select the right scraps containing no detrimental elements to steel,phosphorous,sulpher,tin,chromium and we do not prefer any cast iron which contain high P and c as well.

scrap Melting point %c %Mn %Si %P %S Source Origin
HMS 1250-1350 c 0.16-0.2 0.5-1 0.15-0.2 0.02 0.015 Local/foreign
Shreded 1150-1200 c 0.5-0.55 nil 0.04 max 0.04 max foreign
Bundle 1300-1350 0.1-0.14 nil foreign
Sponge Iron 0.1-0.12 nil 0.04 .03 foreign

                               

HMS1                                                                                  shredded                                                       bundle

Fresh light bundle

 

                                                                                  MELTING PROCEDURE

 

1. After completion of previous heat the furnace is made ready for next heat within 5 minutes time. Charging usually commences with shredded scraps directly put into the furnace by a magnet crane.

3. Subsequent charging of HMS and bundle follow mostly dominated by HMS scrap.

4. At around 60-70 minutes time slag forms and first deslagging is performed. Frequent spattering of molten metal in the furnace opening is a good indication that deslagging should be done

5.After deslagging is finished a sample is taken either by mean of a spoon or a Lollypop sampler and next course of scrap charging entirely depends on the chemistry result. This sample is known as Opening Bath Sample.

A typical OBS can be in the order of the like:

C-0.206/Si:0.047/Mn:0.177/P:0.03/S:0.02

scrap is charged according to the chemistry and at around 15 minutes time second deslagging is performed, and like before a second sample is taken.

8. If the chemistry is found to be matching with the desired chemistry the furnace is heated up to pave way for alloy addition. For an efficient recovery of alloy addition a temperature range of 1585-1600 ᵒC is required.

9. When the time is right alloy addition is done by throwing bags full of alloys and temperature is recorded. The metal is tapped at 1610-1620 ᵒC. we always prefer low tapping temperature because low temperature causes low entrapped oxygen in liquid metal which would make the product brittle.

10. CaSi wire is thrown in ladle to diminish oxygen

 

                                                    

Melting Process                                                                                                      Deslagging

 

 

 

 

 

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