CAJ | 학술논문

根据电弧对基体材料及填充材料的作用过程建立了 CMT 和 CMT+P 过程的有限元模型，其中基于等效热输入原则简化了 CMT 焊接过程中焊丝进退和热输入之间的相互作用过程。对热源的处理中，采用复合双椭球热源模型。基于该有限元模型研究了热循环规律，由此划分出AA7A52母材的焊接热影响区。模拟计算结果与实验结果的不同之处是，冷却过程中出现低频效应，这种低频效应的表现方式为低冷却速率。软化区包括淬火区和过时效区，基板内部的软化范围明显大于基板近表层区域。通过红外测温实验验证了计算模拟结果的准确性。
근거전호대기체재료급전충재료적작용과정건립료 CMT 화 CMT+P 과정적유한원모형，기중기우등효열수입원칙간화료 CMT 한접과정중한사진퇴화열수입지간적상호작용과정。대열원적처리중，채용복합쌍타구열원모형。기우해유한원모형연구료열순배규률，유차화분출AA7A52모재적한접열영향구。모의계산결과여실험결과적불동지처시，냉각과정중출현저빈효응，저충저빈효응적표현방식위저냉각속솔。연화구포괄쉬화구화과시효구，기판내부적연화범위명현대우기판근표층구역。통과홍외측온실험험증료계산모의결과적준학성。
A required finite element method (FEM) model applicable for narrow gap CMT and CMT+P MIX welding was established based on the interactions between arc, base metal and filler metal. A novel method of simplifying wire feeding pulses and heat input pulses was supposed under the conduction of equivalent input. The method together with composed double-ellipse heat sources was included in the model. The model was employed in the investigation of thermal cycling and the identification of the softened zone of AA7A52 base plates. Low-frequency behavior emerged in the form of low-cooling rate sects, which were not expected under experimental conditions. The softened zone including the quenched zone and averaging zone of the base plate was much wider internal the base plate than that close to the surfaces. The reliability of the predictions in thermal cycling was supported by infrared imaging test results of the thermal cycle process.