(西安理工大學(xué) 陜西省電工材料與熔(浸)滲技術(shù)重點(diǎn)實(shí)驗(yàn)室，西安 710048)
摘 要: 采用真空熔煉工藝制備類K445高溫合金，研究熔煉保溫時(shí)間對(duì)其鑄態(tài)組織及硬度的影響。結(jié)果表明，熔體保溫時(shí)間對(duì)合金的相種類沒有影響，合金均由樹枝狀γ基體、彌散分布于基體的γ′相、枝晶間的γ＋γ′共晶、γ′′相、MC碳化物、少量M3B2硼化物等強(qiáng)化相組成；但隨熔體保溫時(shí)間的延長(zhǎng)，枝晶尺寸先減小后增大，MC碳化物含量先減少后增多，γ＋γ′共晶和γ
關(guān)鍵字: 類K445高溫合金；熔體保溫時(shí)間；顯微組織；硬度
similar-K445 superalloy
（Shaanxi Province Key Laboratory for Electrical Materials and Infiltration Technology, Xi’an
University of Technology,Xi’an 710048, China）
Abstract:The effects of melt holding time on the microstructure and hardness of similar-K445 superalloy were investigated. The results show that melt holding time has no effect on the sorts of phases. The as-cast microstructure consists of MC carbide, eutectic γ′, γ′′, a spot of M3B2 borides in dendritic regions and secondary γ′ phase distributed in γ matrix. However, with increasing melt holding time, the sizes of dendrites as well as content of MC carbide increase before reduction, the contents of eutectic γ′ and γ′′ as well as the hardness of the alloys decrease before increase. When melt holding time is 30 min, the alloy gets the finest dendrites, the biggest contents of eutectic γ′ and γ′′, the least content of MC carbide and the highest hardness of HB 381.
Key words: similar-K445 superalloy; melt holding time; microstructure; hardness
