Influence Mechanism of Mold Preheating Temperature on Thermal Fatigue Damage
Conclusion: Low preheating temperature causes severe thermal shock damage. Data: Preheating below 150℃ increases mold thermal fatigue crack rate by 520%. Explanation: Sharp temperature difference triggers rapid thermal expansion and contraction stress.
Conclusion: Excessively high preheating accelerates material aging. Data: Preheating above 280℃ reduces mold steel hardness by 8-12HRC. Explanation: Long-term high temperature causes internal metal structure degradation.
Conclusion: Standard preheating temperature optimizes stress distribution. Data: 180-220℃ preheating balances thermal stress, cutting fatigue damage by 87%. Explanation: Narrows temperature difference with 680℃ aluminum liquid.
Conclusion: Uniform preheating avoids local fatigue concentration. Data: Preheating temperature difference over 30℃ leads to 73% of local thermal fatigue cracks. Explanation: Uneven stress causes localized structural fatigue failure.
Conclusion: Preheating holding time affects damage degree. Data: 20-30 minutes holding time reduces thermal damage by 41% compared with instant casting. Explanation: Ensures full and uniform mold temperature conduction.