New stainless steel seamless pipeline

The new production line of martensitic stainless steel seamless tube KL-HP12CR has excellent weldability, mechanical properties and corrosion resistance. Its weldability is improved by reducing its carbon and nitrogen content. Reducing carbon content also significantly increased the resistance to carbon dioxide corrosion. The corrosion rate was less than 0.127mm / A in a carbon dioxide environment at temperatures up to 160 degrees Celsius. And 2.0MPa. Sulfide stress cracking (SSC) is due to the addition of molybdenum. The new seamless pipe can be used in the hydrogen sulfide environment of pH 4 and 0.001 MPa. The strength of the pipe is X80 grade, and it has enough low temperature toughness when used in pipeline. After heat treatment for a few minutes, the carbon content is reduced. Adding titanium can effectively prevent intergranular stress corrosion cracking (IGSCC) in the heat affected zone. The pipeline is expected to be further used to deliver liquid containing corrosive gases, such as carbon dioxide, which is a cost-effective, high life, and low cost material.


Concerns about the decline in oil resources are increasing, and the temperatures and pressures of oil well and natural gas wells being mined are now reaching unprecedented levels, and liquids generally contain carbon dioxide, causing more corrosion. Therefore, in order to prevent carbon dioxide corrosion of pipelines and collecting pipelines, it is very important to transport liquid before removing corrosive substances and water. In addition, these liquids usually contain trace amounts of hydrogen sulfide and therefore need to prevent chloride stress cracking. In this corrosive environment, for carbon steel pipe materials, the traditional anticorrosion method is to pour liquid into rust inhibitor and rust inhibitor to prevent corrosion. However, this increases production costs, especially for offshore pipelines, so the use of rust inhibitors is less, especially considering life cycle cost. Another reason for not using rust inhibitors is the fear of leakage pollution. Therefore, an economical and economical material is not needed. The existing pipeline corrosion resistant alloys include duplex stainless steel, but the disadvantage is high material cost. On the contrary, martensitic stainless steels usually have poor weldability, requiring preheating and longer post weld heat treatment. Therefore, considering the efficiency of pipeline laying, martensitic stainless steel is seldom used in pipelines. However, martensitic stainless steels are sufficiently resistant to carbon dioxide corrosion and are cheaper than duplex stainless steels.