This page contains a Flash digital edition of a book.
Table 2. Experimental Design for Initial Trials Trial No Trial Description


Ladle


Trial #1 Reduced mass gating with reduced choke area (1.33 sq in.), no frag bar and add 4 bismuth pills Regular ladle 2,750F Trial #2 Reduced mass gating with reduced choke area (1.33 sq in.), no drag bar and add 4 bismuth pills Regular Ladle 2,750F Trial #3 Reduced mass gating with reduced choke area (1.33 sq in.), no drag bar and add 4 bismuth pills Insulated Ladle 2,750F Trial #4 Reduced mass gating with reduced choke area (1.33 sq in.), no drag bar and add 4 bismuth pills Insulated ladle 2,750F Trial #5 Reduced mass gating with reduced choke area (1.33 sq in.), no drag bar and add 4 bismuth pills Insulated Ladle 2,850F Trial #6 Reduced mass gating with reduced choke area (1.33 sq in.), no drag bar and add 4 bismuth pills Insulated ladle 2,850F Trial #7 Reduced mass gating with reduced choke area (1.33 sq in.), no drag bar and add 4 bismuth pills Regular Ladle 2,850F Trial #8 Reduced mass gating with reduced choke area (1.33 sq in.), no drag bar and add 4 bismuth pills Regular Ladle 2,850F


Step 5 – Production Trials Production trial volumes and


details are important in a quality assurance program. Production trials for automotive applications typi- cally require thousands of castings. Some foundries might review data for a whole shift or for several heats to ensure repeatability and reliability of quality. Data tracking includes pouring temperatures, pouring times, microstructure, chemistry, lab tests


related to mechanical properties, and other information. During the preliminary and


production trials, the pouring was done automatically but the metal transfer was manual (by forklift) and, therefore, took more time, resulting in a higher than normal temperature loss. Following the fi ve-step process, key recommendations to reduce the defect included: • Increase the pouring temperatures.


Tap Temp Pour Cup D cup Offset Offset D cup


Offset cup D cup D cup


Offset cup


• Control pouring temperatures (by improving ladle insulation).


• Reduce magnesium additions. • Increase the bismuth addition after MgFeSi treatment.


• Improve the automatic pouring abil- ity to pour in the center of the cup.


• Reduce velocity and turbulence of the metal in the mold.


• Operate the automatic pour- ing system with fully automatic ladle filling.


14 Si SILICON 3.32% 6 CARBON C 3.45% 16 SULPHUR S 0.0138% 25


Mn 0.48%


MANGANESE 42


Mo 0.38%


MOLYBDENUM


MASTER EVERY MELT


Speed up the production process and reduce tap-to-tap time with Hitachi High-Tech spark spectrometers. A range of precision tools that ensure the right ingredients are in the melt, so you can quickly deliver outstanding results.


7 NITROGEN N 0.0064% 15 PHOSPHORUS P 0.0391% The FOUNDRY-MASTER range Optimum Xpert Hitachi High-Tech optical emission spectrometers Pro2 contact@hitachi-hightech-as.com (978) 850-5580


July 2018 MODERN CASTING | 35


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68