P对建筑用低合金钢焊接组织与脆性的影响

发布时间：2018-06-23 02:17

本文选题：元素P + 建筑用低合金钢　；参考：《热加工工艺》2017年21期

【摘要】：通过焊接热模拟研究了不同焊接线能量下建筑用Cr-Mo、Cr-Mo-P低合金钢的显微组织、物相组成和韧-脆转变温度,分析了P的晶界偏聚行为对焊接接头脆性的影响。结果表明,随着焊接线能量的增加,Cr-Mo和Cr-Mo-P低合金钢的韧-脆转变温度都增大;在相同焊接线能量下,Cr-Mo-P低合金钢的韧-脆转变温度都要高于Cr-Mo钢;随着焊接线能量的增加,建筑用Cr-Mo和Cr-Mo-P低合金钢组织由板条贝氏体为主转变为以粒状贝氏体为主,且细条状M/A岛状组织的尺寸呈现逐渐增加的趋势;P的晶界浓度先增加而后降低,在焊接线能量为60 k J/cm时取得最大值;焊接后热处理降低了建筑用Cr-Mo和Cr-Mo-P钢热模拟试样的韧-脆转变温度,这主要与热模拟试样热处理后贝氏体束尺寸基本不变,而M/A组元尺寸减小有关。
[Abstract]:The microstructure, phase composition and toughening brittle transition temperature of Cr-Mo, Cr-Mo-P low alloy steel were investigated by welding thermal simulation under different welding lines. The effect of P's grain boundary segregation on the brittleness of welded joint was analyzed. The results showed that the toughened and brittle transition temperatures of Cr-Mo and Cr-Mo-P low alloy steels increased with the increase of welding line energy. Under the same welding line energy, the toughening and brittle transition temperature of Cr-Mo-P low alloy steel is higher than that of Cr-Mo steel. With the increase of welding line energy, the structure of Cr-Mo and Cr-Mo-P low alloy steel is mainly transformed from slate bainite to granular bainite, and the size of fine strip like M/A islets is gradually increasing; P crystal is gradually increasing. The boundary concentration increases first and then decreases, the maximum value is obtained when the welding line energy is 60 K J/cm, and the heat treatment after welding reduces the toughening and brittle transition temperature of the thermal simulated samples of Cr-Mo and Cr-Mo-P steel, which is basically the same as the bainite size of the heat treated sample, and the decrease of the M/ A component size.
【作者单位】：浙江工业职业技术学院;青岛理工大学;
【基金】：浙江省自然科学基金项目(LQ17E010001)
【分类号】：TG142.1

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