Fe—20Cr—4Al—Y合金的力学性能与含钇相的关系

研究了钇含量对Fe-20Cr-4Al-(0—0.73wt-%)钇合金室温力学性质的影响。结果表明,随钇含量增高,拉伸试样的均匀变形能力略微降低,断裂强度和预缩后的变形量显著下降。这些变化与合金中脆性含钇相对变形和断裂过程的影响有关。控制冶金工艺能改变含钇相的形态。     

Y-Containing Phase in Fe-20Cr-4Al-Y Alloys and Its Effect on Embrittlement

In Fe-20Cr-4Al-Y alloys with (0.13～0.73) wt% Y,Y-containing phase was observed.Its Y content andcrystal structure were identical with those Of YFe_9 phase basically,and microhardness was 4～5 times higherthan that of α-phase matrix.The phase can strongly prevent grain growth and dislocation annihilation,and trapimpurity atoms,as a result,and inhibit the embrittlement caused by treating over 1000℃.     

铁铬铝钇合金研制

通过采用一系列技术措施,解决了长期妨碍Fe-Cr-Al-Y合金制备的工艺难题,冶炼时钇的回收率达60～80%,热锻时铸锭碎裂的情况不再发生。研制的Fe-20Cr-4Al-0.4～0.8Y合金高温寿命与普通Fe-Cr-Al相近,但其高温变形较小,而且室温塑性好(δ≥23%),强度低(σ_b-600MP_a)具有良好的拨丝、缠绕能力。此外,该合金高温脆化和晶粒长大的倾向极小,这一重要特性克服了普通Fe-Cr-Al合金的致命弱点,为取代昂贵的Ni_(30)Cr_(20)合金,为发展无脆化危险的铁素体基高温结构材料提供了可能。     

低脆性FeCrAlY合金的研制

Ｆｅ－１５Ｃｒ－４Ａｌ－Ｙ合克服务了ＦｅＣｒＡｌ合金的高温脆化和４７５℃脆性，热强性和冷加工性也明显改善，ＦｅＣｒＡｌ使用温度高，抗氧化性好等优点则得到保留，还研制了使用温度更高的Ｆｅ－２０Ｃｒ－４Ａｌ－Ｙ，Ｆｅ－２５Ｃｒ－４Ａｌ－Ｙ合金，形成了低脆性合金系列，加入强化元素能进下不提高合金的热强怀，用轻稀土元素代替Ｙ则能降低生产成本，该低脆性合金系列可用于电热、电阻元素件，耐热结构件和耐高温涂层，     

Effect of Y-containing Phase in Fe-20Cr-4Al-Y Alloys on Microstructure and Embrittlement

In Fe-20Cr-4Al-0.5Si-(0.13-0.73)Y alloys,anew phase consisting of 15.8 wt-% Y,65.4wt-% Fe,12.6 wt-% Cr,4.4 wt-% Al and 1.4wt-% Si was observed with its Y-content and crys-tal structure being identical with those ofYFe_9 phase basically and the microhardness being4-5 times higher than that of α-phase matrix.It is akind of stable particles (2-10 μm) dispersed overthe matrix.For Y-free or less alloy,the plasticity droppedsharply after high temperature treatment,while theplasticity is retained for the alloys containing0.41-0.73 wt-% Y treated below 1340℃,becausethe Y-containing particles can strongly preventfrom grain growth,and dislocation annihilation,and trap impurities.If treatment temperature ishigher than 1340℃,however,these actions will dis-appear owing to the melting of the particles.     

低脆性FeCrAlY电热合金的研制

Ｆｅ－１５Ｃｒ－４Ａｌ－Ｙ合金克服了ＦｅＣｒＡｌ合金的高温脆化和４７５℃脆性，热强性和冷加工性也明显改善，ＦｅＣｒＡｌ使用温度高，抗氧化性好等优点则得到保留。还研制了使用温度更高的Ｆｅ－２０Ｃｒ－４Ａｌ－Ｙ和Ｆｅ－２５Ｃｒ－４Ａｌ－Ｙ合金，形成了低脆性合金系列。加入强化元素能进一步提高合金的热强性，用轻稀土元素代替Ｙ则能降低生产成本。合金生产中的工艺困难已经解决，现已投入批量生产。合金用于电热、电阻元件，耐热结构件和耐高温涂层。用它代替Ｎｉ—Ｃｒ系合金可降低元件成本，提高其使用温度和服役寿命。