CAJ | 학술논문

　　低镍奥氏体不锈钢冷却模式为先析出δ铁素体，随后转变为奥氏体，晶核中的δ铁素体被保存下来。随着冷却速度的变化，凝固模式发生变化。在冷却速度不太快的近表面层，可得到接近平衡态的枝晶组织，残留δ铁素体为骨架形或蠕虫状，奥氏体全部为δ铁素体通过固态相变转变而来。在冷却速度较快的表面层，凝固模式偏离平衡态，δ铁素体作为先析出相在液相中形核长大的同时，剩余的液相转变为共晶奥氏体。
　　저얼오씨체불수강냉각모식위선석출δ철소체，수후전변위오씨체，정핵중적δ철소체피보존하래。수착냉각속도적변화，응고모식발생변화。재냉각속도불태쾌적근표면층，가득도접근평형태적지정조직，잔류δ철소체위골가형혹연충상，오씨체전부위δ철소체통과고태상변전변이래。재냉각속도교쾌적표면층，응고모식편리평형태，δ철소체작위선석출상재액상중형핵장대적동시，잉여적액상전변위공정오씨체。
During the cooling process, ferrite is the first phase to precipitate in low nickel austenitic steel, then it will be transformed into austenite and delta-ferrite in the nucleus is retained. With the change of colling rate, the solidification modes changes. Near the surface where the colling rate is not high, the near-bal?anced dendrite structure can be obtained.The retained delta-ferrite are vermiform or of skeleton frame and all austenite are transformed from delta-ferrite by solid phase transformation. On the surface where the colling rate is very high, the solidification mode deviate from the balance;as primary-precipitated phase, delta-fer?rite form first from the liquid while the remaining liquid phases are transformed to eutectic-austenite.