美国公司生产了一种新型钢,代号为PH15-7,可供飞行速度M=4及飞行时加热达550℃的飞机及火箭制造蒙皮和结构的受力构件之用。据该公司宣称,这种新型钢的价格较钛合金贱9倍,易于加工,而且具有与17-7PH号不锈钢相同的抗蚀性。 PH15-7号钢含有15％的铬及7％的镍,添加1.2％的铝,便可达到至最高强度的淬火。由于含有2.5％的钼,温度约在550℃以下能保 U.S. companies have produced a new type of steel, codenamed PH15-7, for aircraft and rockets that fly at speeds of M = 4 and up to 550 ° C during flight. According to the company, the new steel is priced nine times cheaper than titanium and is easy to machine and has the same corrosion resistance as stainless steel 17-7PH. PH15-7 steel containing 15% chromium and 7% nickel, adding 1.2% of the aluminum, can reach the highest strength quenching. With 2.5% molybdenum, the temperature is about 550 ℃ below the guarantee