论文部分内容阅读
1Cr12Ni3Mo VN(S/SJ2)钢是一种含有12%Cr的低碳马氏体不锈钢,在航空发动机中广泛使用。本文对1Cr12Ni3Mo VN钢板材TIG焊接试样进行了高温瞬时拉伸试验、高温持久拉伸试验以及组织分析,研究了焊接接头的显微组织和高温性能。结果表明:拉伸试验时断裂均发生在热影响区的回火区。用TIG焊接1Cr12Ni3Mo VN钢能获得高温性能良好的焊接接头,其焊接接头的高温抗拉强度为766.7 MPa,与母材相当。高温持久拉伸时焊接接头在500℃、负载400 MPa条件下,蠕变寿命为240.71 h,与1Cr12Ni3Mo VN钢母材在同等条件下的蠕变寿命248.56 h相当。母材与焊接接头高温瞬时拉伸试样、高温持久拉伸试样的断口形貌均为浅韧窝形。室温下母材组织为具有良好综合力学性能的回火索氏体,焊缝组织为铸态的板条马氏体。高温瞬时拉伸及高温持久拉伸后焊缝马氏体组织明显长大,但随高温时间的变长组织长大趋缓,其长大程度变化不明显。
1Cr12Ni3Mo VN (S / SJ2) steel is a 12% Cr low carbon martensitic stainless steel that is widely used in aeroengines. In this paper, TIG welding of 1Cr12Ni3Mo VN steel plate samples were subjected to high temperature transient tensile test, high temperature tensile test and microstructure analysis of the microstructure and high temperature performance of welded joints. The results show that the fracture occurred in the tempering zone in the heat affected zone during the tensile test. Using TIG welding 1Cr12Ni3Mo VN steel to obtain a good high-temperature performance of the welded joints, the high temperature tensile strength of welded joints 766.7 MPa, and the base metal. The creep life of the welded joints at 240 ℃ and 400 ℃ under the condition of 500 ℃ and 240 MPa is the same as that of the 1Cr12Ni3Mo VN steel base under the same conditions for a long time of 248.56 h. Base metal and welded joints at high temperature instantaneous tensile specimens, high temperature tensile specimens of the fracture surface morphology are shallow ductile. The matrix at room temperature is a tempered sorbite with good mechanical properties. The weld microstructure is as-cast lath martensite. The martensitic structure of the weld obviously grew up after the high-temperature instantaneous stretching and the high temperature permanent stretching, but the growth of the tissue grew slowly with the increase of the high temperature time, and the growth of the martensite did not change obviously.