18-8型奥氏体不锈钢锅炉管服役特性研究(一)

STUDY ON SURVICING PROPERTIES OF BOILER TUBES MADE FROM 18-8 TYPE AUSTENITIC STAINLESS STEEL

对18-8型奥氏体不锈钢锅炉管的服役特性进行研究,其主要包括奥氏体不锈钢锅炉管服役过程中组织演变规律、力学性能变化、组织性能变化及不锈钢锅炉管制造工艺差异对服役安全性的影响。研究结果表明,随着服役期的延长,材料的σ相逐渐析出,材料脆化,抗腐蚀能力降低;固溶处理工艺不当时,易在运行中产生裂纹;未施行去应力处理时,会加大应力腐蚀风险;焊接时应注意线能量和冷却速度的控制。

The main conclusions in this 《study on servicing properties of boiler tubes made from 18 -8 type austenitic stainless steel》 have been briefly presented,including mainly the influence of changing regularity of micro - structure, the variation of mechnical behavior, the variation of structural properties in the servicing process of boiler tubes made from austenitic stainless steel,as well as the difference in manufacturing process of boiler tubes made from the said steel, upon safety in the survicing period. Study shows that as in the following：along with the lengthening of servicing term, the δ - phase in matirials will be graduall separated out,enbritlement of materials will be appear,and the anti-corrosion ability will reduce,moreover,improper solid - solution process may result in cracking in operation,in the event of destress process being not carried out, the risk of stress corrosion may be in-creased;during the time of welding,attention should be paid to control of the line energy consumption and the cooling speed.