一、前言半奥氏体型沉淀硬化不锈钢Cr15.5Ni4.5Mo3N(相当于美国AM355)是一种新型的高强度不锈钢。在常温下它的强度值相当于普通奥氏体不锈钢的两倍多,塑性也相当好,并且在427℃的高温下,仍能保持高强度。此外,它的耐腐蚀性能及加工成形性能也比较好。也就是说,这种钢既具备了马氏体的高强度优点,又具备了奥氏体钢的耐腐蚀和易成形等优点。因 I. Introduction Semi-austenitic precipitation hardened stainless steel Cr15.5Ni4.5Mo3N (equivalent to the United States AM355) is a new type of high-strength stainless steel. Its strength at room temperature is equivalent to more than twice that of ordinary austenitic stainless steel, its ductility is also quite good, and its strength remains high at 427 ° C. In addition, its corrosion resistance and forming properties are also better. In other words, this steel not only has the advantages of high strength martensite, but also has the advantages of austenitic steel corrosion-resistant and easy to shape. because