日本计划建设大规模的地热发电站,必须解决的技术课题之一是提高地下套管的耐久性。目前使用不锈钢管,但它在高温高压环境下易产生腐蚀裂纹,为此开发了钛合金管。管材的成形方法有轧制法、UO压力成形法及压力弯曲法等,前两种方法需用大型设备,不适用小批量生产,为此开发了用小 Japan plans to build large-scale geothermal power plants, one of the technical issues that must be solved is to improve the durability of underground casing. Currently using stainless steel pipe, but it is easy to produce corrosion cracking under high temperature and pressure environment, for which the development of titanium alloy tube. Pipe forming method rolling method, UO pressure forming method and the pressure bending method, the first two methods require large equipment, not suitable for small batch production, for which the development of a small