Metallurgical Optimization of Microalloyed Steels for Oil and Gas Transmission Pipelines
he production of microalloyed steels for oil and gas transmission pipelines has increased significantly over the past years. With more and more countries developing their own capabilities to produce pipeline steels to support their own internal pipeline infrastructure development, there has been an increase of steel producers working to develop their own capabilities to produce microalloyed steels for this application. However, to achieve the desired mechanical property attributes for transmission pipeline applications utilizing a cost effective approach requires metallurgical optimization of the microalloyed steels. To achieve metallurgical optimization a basic understanding is required in the design of a cost effective alloy and then the proper processing of that alloy design to achieve the optimum microstructure/mechanical properties. In this sense, many producers in the world, especially those who have only recently, in the past 10 years, developed their capability to produce microalloyed transmission pipeline steels still do not achieve metallurgical optimization of their alloy and process. This results in yield losses due to failures, inefficient processing causing productivity losses and additional expensive additions of alloys to compensate for failures and process inefficiencies.Since the supplier of plate/coil has the largest percentage effect on the final cost of the pipe, the steel producer must understand proper alloy, microstructure,and process design to produce a uniform and stable plate/coil to be used in pipe production. This means that strength,toughness and microstructure must be uniform down the length, across the width and through the cross section. Metallurgical optimization is achieved when this uniformity is achieved with a cost effective approach.Counter to that, non-uniformity results in pipe forming, welding, expansion, mechanical property and production issues resulting in downgraded pipe and cost overruns in pipemaking.This paper will describe targets for plate/coil uniformity for pipe production and show examples of pipe issues when uniformity cannot be achieved. Key plate/coil attributes will be identified along with guidelines on alloy design and key processing parameters and targets that need to be considered to work toward metallurgical optimization. Examples will be used to illustrate the thought process in alloy/process design for metallurgical optimization.
microalloy niobium pipeline solubility grain size rolling schedule
STALHEIM,Douglas
DGS Metallurgical Solutions Inc.,15003 NE 10th Street,Vancouver,WA 98684 USA
国际会议
The 6th International Conference on High Strength Low Alloy Steels(第六届高强度低合金钢国际会议HSLA Steels2011)
北京
英文
148-153
2011-05-31（万方平台首次上网日期，不代表论文的发表时间）