Furukawa-Sky Review No.2 (April 2006)
技術論文
ろう付加熱後に熱処理を施したAl-Mn-Cu合金の粒界腐食感受性
Intergranular Corrosion Susceptibility of Al-Mn-Cu Alloy Subjected to Heat Treatment after Brazing Heating
1,144KB）- 大谷 良行
Yoshiyuki Oya - 田中 哲
Satoshi Tanaka - 二宮 淳司
Junji Ninomiya - 土公 武宜
Takeyoshi Doko
地球温暖化対策の一環としてカーエアコンの冷媒がフロン系冷媒からCO2冷媒に切り替わった場合，動作温度が180℃まで達すると言われている。カーエアコン用アルミニウム材料の使用温度環境での金属組織変化に伴う腐食挙動把握を目的として，600℃，3minのろう付加熱後に180℃において熱処理を行ったAl-Mn-Cu合金の粒界腐食感受性をアノード溶解試験によって調査した。
Mn，Cu添加量の増加およびろう付加熱後の180℃での熱処理時間の増加とともに粒界腐食感受性は増大し，TEM観察により，Al-Cu系金属間化合物の析出量増加，粒界への優先析出が確認された。粒界におけるAl-Cu系金属間化合物の析出によって，粒界に沿ったCu欠乏層が形成されたことが，粒界腐食感受性が増加した理由であると考えられる。
As one of the measures against global warming, a changeover of the refrigerant of car air conditioners is taking place from freon-based refrigerants to carbon dioxide. In this case, the operating temperature is said to reach 180℃. Aluminum materials for car air conditioners will experience a change of metallic structure in such a service temperature environment. To understand the corrosion behavior accompanying the metallic structure change, an Al-Mn-Cu alloy was subjected to a heat treatment at 180℃ after brazing heating at 600℃ for 3 minutes, and its intergranular corrosion susceptibility was investigated by an anodic dissolution test.
The intergranular corrosion susceptibility increased with an increase in the amount of Mn and Cu added and an increase in the heating time at 180℃ after brazing heating. TEM observation verified an increase in the amount of precipitation of Al-Cu intermetallic compounds and their selective precipitation at the grain boundary. The reason for the increase of intergranular corrosion susceptibility is thought to be the Cu-depleted zone formed along the grain boundary by the precipitation of Al-Cu intermetallic compounds at the grain boundary.
技術論文 / Technology Articles
- 缶胴のボトムしわ発生に及ぼすアルミニウム合金板の材料特性の影響
Effect of Material Properties of Aluminum Alloy Sheet on Bottom Wrinkling of Can Body - ワックス添加プレコート材の潤滑特性
Lubrication Properties of Aluminum Sheets Pre-coated with Wax - 車載高圧水素タンク用6061合金の疲労特性
Fatigue Properties of 6061 Aluminum Alloy for On-board High Pressure Hydrogen-Gas Tanks - ろう付加熱後に熱処理を施したAl-Mn-Cu合金の粒界腐食感受性
Intergranular Corrosion Susceptibility of Al-Mn-Cu Alloy Subjected to Heat Treatment after Brazing Heating - ターボチャージャ用高精度コンプレッサホイール鋳物の製造技術開発
Development of the Manufacturing Technology of the Precision Compressor Wheel Casting for Turbo Charger