抗酸性X70MS直缝埋弧焊管的研制

采用低C、低Mn、合金化设计和超洁净化冶炼制造的X70MS抗酸性钢板,通过控制焊接接头硬度、焊接热输入以及钢管残余应力等,开发制造出了X70MS抗酸性直缝埋弧焊管,并对焊管管体和焊缝组织性能进行了研究。结果表明,管体和焊缝的硬度均小于250HV10,0℃下母材冲击功大于410 J,焊接接头冲击功大于168 J;按照NACE-0284标准进行HIC测试,管母和焊接接头裂纹敏感率(CSR)、裂纹长度率(CLR)及裂纹厚度率(CTR)均为0;按照NACE-0177标准进行SSCC测试,采用A溶液,在72%ReL及90%ReL载荷下,管母和焊接接头均未出现断裂,管材表现出良好的力学性能和耐酸性。

Development of X70MS Grade Acid-resistance SAWL Pipe

The X70MS grade acid-resistance steel plate was produced by using the technology of low carbon, low manganese, microalloying design and clean smelting. By controlling the hardness of welded joints, welding heat input and the residual stress of steel pipe, the X70MS grade acid-resistance SAWL pipe was developed. Test results showed that the hardness of pipe body and weld both are less than 250 HV10. Under 0 ℃, the impact energy of base metal is greater than 410 J, and the impact energy of welded joint is greater than 168 J. The HIC tests were conducted in accordance with the NACE-0284 standard, the cracking sensitivity （CSR） of base metal and welded joints, the crack length ratio （CLR）, and the crack thickness ratio （CTR） are all zero; The SSCC tests were conducted in accordance with NACE-0177 standard by using A solution under 72% ReL and 90% ReL loading, the fracture did not appear in base metal and welded joints, the pipes showed good mechanical properties and acid resistance.