【摘要】：對一種新型鎳基耐蝕合金X-2#與625合金手工氬弧焊接接頭進行拉伸性能和硬度的測試,并結(jié)合OM,SEM和EDS分析等手段研究了焊接接頭的組織和性能.結(jié)果表明,X-2#/625異種金屬焊接焊縫重熔區(qū)等軸晶組織增多,有利于提高焊縫區(qū)強度.X-2#合金一側(cè)熔合區(qū)組織過渡良好,而625合金一側(cè)晶界有Nb C和Laves相析出,影響材料的力學性能.熱影響區(qū)在靠近重熔區(qū)附近的晶粒由于受2次熱循環(huán)的影響,出現(xiàn)晶粒長大現(xiàn)象,而X-2#合金一側(cè)熱影響區(qū)的熱穩(wěn)定性較好.625合金母材晶粒細小導致其熱影響區(qū)晶粒長大明顯,從而使625合金一側(cè)熱影響區(qū)的Vickers硬度值降低.X-2#/625焊接接頭在室溫到700℃下的抗拉強度均低于2側(cè)母材,焊縫區(qū)為接頭最薄弱環(huán)節(jié),斷口形貌均為韌窩狀的韌性斷口.
[Abstract]:The tensile properties and hardness of a new type of nickel base corrosion resistant alloy X-2# and 625 alloy were tested. The microstructure and properties of the welded joints were studied by means of OMU SEM and EDS analysis. The results show that the increase of equiaxed grain structure in weld remelting zone of #625 dissimilar metal welding is beneficial to increase the strength of weld zone. The microstructure transition of the fusion zone on the side of X-2# alloy is good, while NB C and Laves phase are precipitated at the grain boundary of 625 alloy, which affects the mechanical properties of the material. The grain growth in the heat-affected zone near the remelting zone is due to the effect of two thermal cycles, while the thermal stability of the heat-affected zone on the side of X-2# alloy is better than that in the heat-affected zone. The smaller grain size of the base metal in the X-2# alloy leads to the obvious grain growth in the heat-affected zone. Thus, the Vickers hardness of 625 alloy on one side of heat-affected zone was reduced. The tensile strength of the welded joints at room temperature to 700 鈩，

本文編號：2133386