표제지
초록
목차
제1장 서론 14
1.1. 연구배경 14
1.2. 연구내용과 논문의 구성 20
1.3. 참고문헌 21
제2장 각종 주물사의 특성과 주강품 주조에 적합한 인공사 선택에 관한 연구 27
2.1. 서론 27
2.2. 실험방법 32
2.2.1. 실험용 주물사 준비 32
2.2.2. 주물사 물성 비교 평가 36
2.2.3. 주형강도 시험 36
2.2.4. 주물사 내구성 평가 37
2.2.5. 주물사의 내열 특성 평가 44
2.2.6. 주강 시험편 주조 소착결함 발생율 비교 시험 45
2.3. 실험결과 및 고찰 49
2.3.1. 각종 주물사의 물성 49
2.3.2. 각종 주물사의 주형강도 특성 65
2.3.3. 각종 주물사의 내구성 69
2.3.4. 각종 주물사의 내열특성 80
2.3.5. 주강 시험편 주조 소착결함율 87
2.4. 결론 92
2.5. 참고문헌 94
제3장 아크용사법에 의한 구형 인공사 제조에 관한 연구 101
3.1. 서론 101
3.2. 실험방법 108
3.2.1. 인공사 시작품 제조 108
3.2.2. 비교 평가용 상용 인공사 준비 110
3.2.3. 인공사 물성 비교 평가 119
3.2.4. 주형강도 시험 119
3.2.5. 인공사 내구성 평가 120
3.2.6. 인공사의 내열 특성 평가 121
3.2.7. 주강 시험편 주조 소착결함 발생율 비교 시험 122
3.3. 실험결과 및 고찰 125
3.3.1. 인공사의 물성 125
3.3.2. 인공사의 주형강도 특성 136
3.3.3. 인공사의 내구성 140
3.3.4. 인공사의 내열특성 147
3.3.5. 주강 시험편 주조 소착결함율 155
3.4. 결론 160
3.5. 참고 문헌 162
제4장 종합결론 171
Abstract 173
본 연구와 관련된 저자의 발표논문 및 학술발표 178
Table 2-1. Manufacturing method, country of origin, raw minerals by type of foundry sand used in the experiment. 34
Table 2-2. Classification of various spherical artificial sand manufacturing methods and schematic diagram of major processes. 35
Table 2-3. Physical properties of alkali phenolic no-bake resin binder used in the experiment. 39
Table 2-4. Test results of various foundry sand properties. 48
Table 2-5. Sand burn-in defect rate of various foundry sand by steel casting test piece casting test 90
Table 3-1. WD-XRF, XRD, 1,000℃ LOI test results of raw minerals. 113
Table 3-2. Mineral mixing rate and chemical composition of molded object for manufacturing prototype of artificial sand. 114
Table 3-3. Classification manufacturing methods and raw mineral, manufacturing country of various commercial spherical artificial sand... 118
Table 3-4. Test results of various artificial sand properties. 132
Table 3-5. Sand burn-in defect rate of various artificial sand by steel casting test piece casting test. 158
Fig. 2-1. Applied industries for heavy steel castings. 31
Fig. 2-2. Pattern drawing and molding sand compaction tester used by test specimens during production of mold compressive strength. 40
Fig. 2-3. Pot mill used in foundry sand crushing rate test. 41
Fig. 2-4. Examples of sand burn-on and sand burn-in on the surface of heavy steel castings.... 42
Fig. 2-5. Example of sand burn test piece casting test process, sand burn test piece drawing and mold schematic diagram.... 47
Fig. 2-6. Graph of Al₂O₃ content and refractoriness by manufacturing method and mineral composition of artificial sand.... 59
Fig. 2-7. Graph of SiO₂ content and refractoriness by manufacturing method and mineral composition of artificial sand.... 60
Fig. 2-8. SEM images of various foundry sand. (a) 소결인공사 A, (b) 소결인공사 B, (c) 소결인공사 C1, (d) 소결인공사 C2,... 63
Fig. 2-9. SEM images of artificial sand manufactured by the spray drying & sintering process and artificial sand manufactured by melt... 64
Fig. 2-10. Compressive strength of various foundry sand molds. (molding process : alkali phenolic no-bake resin and ester curing agent,... 68
Fig. 2-11. Crushing test results by pot mill of various foundry sand. 72
Fig. 2-12. 1,100℃ heating & quenching test results of various foundry sand. 76
Fig. 2-13. SEM image of artificial sand by 1,100℃ heating & quenching tested.... 77
Fig. 2-14. TMA(thermo mechanical analysis) result of artificial sand. 78
Fig. 2-15. DSC(differential scanning calorimetry) result of artificial sand. 79
Fig. 2-16. Fused compound generation rate of various foundry sand by sintering test temperature. 83
Fig. 2-17. Fused compound generation rate of various foundry sand by 1,500℃ burn heat resistance test. 84
Fig. 2-18. Sand burn-in defect rate of various foundry sand by steel casting test piece casting test... 91
Fig. 3-1. Manufacturing process flow diagram of prototype of artificial sand. 111
Fig. 3-2. Shape of raw minerals for electric arc atomization. (a) Calcined Bauxite (b) Pyrophyllite [Gray grade]... 112
Fig. 3-3. Equipments for manufacturing molding object. (a) Jaw crusher (b) Pin mill (c) Disc mill... 115
Fig. 3-4. Equipments for manufacturing prototype of artificial sand. (a) Directly heated arc furnace (b) Twist screen (c) Batch mixer 116
Fig. 3-5. Manufacturing process of prototype of artificial sand by electric arc atomization.... 117
Fig. 3-6. Example of sand burn test piece casting test process, sand burn test piece drawing and mold schematic diagram.... 124
Fig. 3-7. Graph of chemical content and refractoriness of various artificial sand.... 133
Fig. 3-8. SEM images of various artificial sand. (a) 인공사 시작품 A, (b) 인공사 시작품 B,... 135
Fig. 3-9. Compressive strength of various artificial sand molds. (molding process : alkali phenolic no-bake resin and ester curing agent,... 139
Fig. 3-10. Crushing test results by pot mill of various artificial sand. 143
Fig. 3-11. 1,100℃ heating & quenching test results of various artificial sand. 146
Fig. 3-12. Examples of sintered sand lump and sand defect on the surface of heavy steel castings.... 150
Fig. 3-13. Fused compound generation rate of various artificial sand by sintering test temperature. 151
Fig. 3-14. Fused compound generation rate of various artificial sand by 1,500℃ burn heat resistance test. 154
Fig. 3-15. Sand burn-in defect rate of various artificial sand by steel casting test piece casting test.... 159