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本文介绍了能提高奥氏体耐热变形钢高温持久强度的高温固溶析出处理方法。通过试验得出:4Cr25Ni20变形钢经过高温固溶析出处理后,982℃,41MPa的持久破断时间由原变形态的13h提高到191h。2Cr25Ni20变形钢经过高温固溶析出处理后,900℃,49MPa的持久破断时间间由原变形态的3.6h提高到127h。证明高温固溶析出处理后变形钢的高温持久强度得到明显的提高,可达到同钢种的离心铸造材的高温持久强度。分析认为变形钢经高温固溶析出处理后,由于在粗大晶粒的晶界上析出了锯齿形连续的M_7C_3、M_(23)C_6碳化物,使晶界强化,在高温应力作用下晶界不易产生空洞和裂纹,因此钢的高温强度得到提高。
This paper introduces a high temperature solution treatment method to improve the high temperature strength of austenitic heat-resistant steels. The results show that the permanent breaking time of 982 ℃ and 41MPa increases from 13h to 191h after deformation treatment of 4Cr25Ni20 deformed steel at high temperature. 2Cr25Ni20 deformed steel after high temperature solid solution precipitation treatment, 900 ℃, 49MPa lasting breaking time from the original form of 3.6h increased to 127h. It is proved that the high temperature permanent strength of the deformed steel after the high temperature solid solution precipitation treatment is obviously improved, and the high temperature lasting strength of the centrifugal casting material of the steel can be achieved. The analysis shows that the precipitated Mg_7C_3 and M_ (23) C_6 carbides are precipitated on the grain boundaries of the coarse grains after the high temperature solid solution precipitation treatment on the deformed steel. The grain boundaries are strengthened and the grain boundaries are hard to be worked under high temperature stress. Produce voids and cracks, so the high temperature strength of steel is improved.