Spokane Steel Foundry Division - Melting and Pouring

by Dave Davis, Pouring Operations

Spokane Industries Steel Castings Division boasts two electric arc furnaces. We utilize one for our steel casting products and we use the other one for our high chrome iron wear parts. Each furnace has been updated with a touch screen computer which controls the tap position, amperage, and also controls all of the roof movements for charging the furnace. We also can keep track of which alloys are used in each heat, which heats we have run along with brick life for each furnace which helps maintain and control furnace life.

Our Steel Castings Division averages 5 tons of material per heat. We use only recycled steel in the charge that is loaded from the scrap pile once it is weighed. Our overhead crane transports it down to the furnace area and using an orange peel type bucket it is positioned over the furnace for loading. Once the furnace is loaded and running it takes about ninety minutes from start to finish during which time we monitor temperature and also the chemistry of the melt.

There are three different samples taken by the melters. The first is to check for carbon content and chemistry for the blow down. We blow down at least 30 points - this is to ensure proper cleansing of the metal. The melters then take the chemistry and calculate exactly what alloys are needed to meet our customers steel casting specification. After we tap the furnace, another final sample is taken to make sure that each and every element is within customer specification.

At Spokane Industries Steel Castings the melters use an ARL 3,460 spectrograph to analyze each sample taken. Once the final sample is taken and verified to be within customers specification the steel casting is then allowed to be poured.

The metal is transferred to the proper designated station by an overhead crane. First the crane retrieves up the holding ladle from the ladle area and transports it to the furnace for filling. Once the chemistry sample has been taken it travels to the designated pouring station to wait for verification that everything is within specification before continuing on and pouring.

Spokane Industries Steel Castings Divisions' ladle department is equipped to pour an array of weights from 50Lbs to 11,500Lbs. We have many different ladles at our disposal. The side pour ladles range from 500Lb capacity to 1,200Lbs and our bottom pours can accommodate 1,200Lbs and all the way up to 12,000Lbs. We also have a 3,000Lb lip pour and a 3,000Lb tea pot.

Our ladles are prepared using the board lining materiel that in turn provides a cleaner metal with less refractory. It also allows ease of building and faster turnaround times. This method accommodates both steel and iron pours. Each heat poured is monitored for which ladle is used, who poured, and we keep track of temperature to insure that a quality casting is produced.

Our pouring ranges vary by part and specifications. The steel can be anywhere from 2,850 to 2,920 degrees and the high chrome iron range is 2,500 to 2,560. The temperature is taken throughout the heat so as to maintain quality and consistency.

Andy Kruse, Process Control Engineer states "we also utilize a digital scale on our crane to monitor and capture weights which allows us to be more accurate with pour weights and allows us to not have short pours or a lot of end metal. This information also helps the melt side as well. We can maximize the heat size to what has to be poured and reduce end metal. We can also capture melt loss - all of which helps us to be more efficient and conserve power in this ever-changing steel casting industry."

Spokane Industries Steel Castings Division is a well managed, state of the art facility prepared to meet and exceed our customers expectations and specifications. On-time delivery, fast turn-around and industry leading quality controls are what our customers expect and exactly what we deliver.