Abstract:
Pre-analysis and improvement of casting system design helps to check the effectiveness
of the design and to take proper measures before actual casting of the product. Akaki
Basic Metals Industry cast different product based on customer order. According to the
2013/14 (Ethiopian Calendar) production reports 149 cast parts were cast and 79.20% of
cast parts was rejected, and 20.80% of the products was accepted in a foundry. From the
rejected cast parts, a 75.42% rejection rate was registered for flange rollers, therefore the
casting system design for flange rollers was studied in detail. The main purpose of this
research was to analyze and improve the casting system design of flange roller using a
Computer-Aided simulation approach, and conduct experimental validation in case
foundry. To this end, the existing casting system design of the flanged roller was modeled
using CATIA V5 and simulation analysis have been conducted using ProCAST 2019,
while the casting process control is examined through photographic analysis, cause-and
effect diagram, and why-why analysis for determining the root cause. The analysis result
indicates the major contributor to the cast part rejection was the poor design of the casting
system design of the flange roller. To improve the gating system a new isolated tube-like
gating system placed inside the mold was developed to deliver molten metal into the mold
cavity, with sand having a Grain Fine Number greater than 60%. Actual casting of flange
roller and simulation-based validation using new gating system indicate that sound
casting with yield improvement of 10.89% was achieved as compared to the existing
casting approach, and the molten temperature were maintained during fill time and
reduced sand erosion. Molten metal consumption by gating system were reduced from
56.89% to 19% (37.89% reduction), and consumption by cast part is improved from
43.11% to 64% (20.89% improvement). The new casting system design for the flange
roller increase product output, i.e. instead of casting two flange roller in existing casting
system design the new developed casting system design cast three flange roller.
