新型PFT-1高强度耐热合金钢的应用

APPLICATION OF NEW HIGH STRENGTH HEAT-RESISTANT ALLOY STEEL PFT-1

ＰＦＴ－１钢是在ＨＫ４Ｄ钢的基础上加入少量Ｎｂ，Ｔｉ等元素，以改善碳化物强化相的种类、形态和分布的一种新型高强度耐热合金钢。为考察该钢种的长期使用性能，并为设计使用提供稳定可靠的高温强度数据，对该合金钢进行了在９５０°Ｃ下时间长达３０ ０００ ｈ的持久强度试验。考察表明，ＰＦＴ－１钢持久强度分别是 ＨＫ４０钢和ＨＰ＋Ｎｂ钢的１５和１．２倍左右。特别是已在大庆石油化工总厂服役３５ ０００ ｈ的ＰＦＴ－１钢转化炉管，其解剖性能仍然比未服役的ＨＫ４０钢和ＨＰ＋Ｎｂ钢的持久强度高．这充分证明新钢种的组织和性能具有长期稳定的特点。此外，ＰＦＴ－１钢的热疲劳性能优于ＨＫ４０钢，抗氧化性能则与ＨＫ４Ｄ钢及ＨＰ＋Ｎｂ钢相当，其焊接性能良好。用以代替ＨＫ４０钢和ＨＰ＋Ｎｂ钢生产大直径转化炉管，可以强化石油化工流程的工艺参数，从而取得十分明显的经济效益。

The PFT-l steel is a new type high strength heat-resistant alloy steel produced by adding a small amount of Nb and Ti elements into the HK40 steel to improve the kinds, forms and distribution of the carbonate intensified phase. In order to investigate the long-term service characteristics of this steel, and to supply reliable data of high temperature strength for design, a 3000 h test of long-term permanent strength of the steel at 950℃ was carried out. The results showed that the permanent strength of the PGT-1 steel is 1. 5 and 1. 2 times of those of the HK40 and HP + Nb steels respectively. Especially, the microscopic characteristics of the steam reformer tubes of PFT-l steel aller running over 35 000 hours in Daqing General Petrochemical Works was even higher than those of the unserviced HK40 and HP + Nb steels. These fully verified that the organism and characteristics of the new kind steel is characterized by long-term stability. In addition, the thermal fatigue characteristics of the PFT-l steel is superior to that of the HK40 steel, while its oxidizing resistance corresponds to those of the HK40 and HP + Nb steels, and having good welding characteristics. This new steel can be used as an alternative of HK40 and HP + Nb steels for manufacturing large diameter steam reformer tubes and strengthening petmechemical process parameters to achieve evident economic benefits.