Heat treatment of oil casing use continuous automatic production, product performance testing by sampling of ways after the heat treatment, can not be 100% product performance validation, strict control of all the relevant factors in the production process of heat treatment is the key to a stable and reliable pipe performance guarantee.
By taking effective measures, from the performance characteristics of heat treatment production line, maintenance and use of heat treatment process and quality management, production management and other aspects of personnel strictly controlled to ensure a reliable product performance, users get the full recognition. Oil casing go down and service in the process to withstand the internal pressure, external pressure, bending, rotation, wear, corrosion, and other harsh conditions ", so the pipe properties (including mechanical properties, resistance to collapse within yield, resistance to corrosion and other use performance) has a very high reliability requirements.
Especially in recent years exploration and production in deep, ultra deep, deep sea and contain hydrogen sulfide, carbon dioxide and other complex geological oil and gas fields, the demand for steel and above N800 and P110 high grade products for more and more common, and these must be in accordance with the standard grade Full length heat treatment. Heat treatment process are "special process" group in the entire production process of oil casing, since the performance of the control steel heat treatment after only indirectly by controlling the heat treatment process parameters, and only sampling but not 100% verification performance. Casing and tubing specification ISO 11960 (API 5CT) will also heat treatment step is defined as "a step that requires acknowledgment." Given the importance and the special nature of the heat treatment process, oil casing manufacturing process must be carefully controlled and confirmed, in order to ensure a reliable and stable performance steel.
Technical characteristics and the major requirements of the oil casing heat treatment equipment is more automatic continuous production mode, not only the production of high efficiency, yield, and product quality and stability provide a solid foundation. Typically a production line of steel heat treatment up to 5 to 250,000 t, the main equipment is including heat treatment furnace and quench cooling. For maximum productivity, heat treatment furnace usually stepping continuous heat treatment furnace, quench hardening mechanism with horizontal cooling both inside and outside, to ensure uniformity of the overall performance of steel after quenching.
Steel heat treatment furnace is the key equipment throughout the production process. Where the effective temperature uniformity of the heating zone, accuracy and stability, the accuracy of the production rhythm (rhythm reflecting pipe heating and holding time), an oxidizing atmosphere heating zone control characteristic parameters will have a significant impact on the quality of steel. Oil casing pipe heat treatment properties of the heating temperature, API oil casing stringent performance requirements, heat treatment furnace temperature control accuracy should reach ± 5 , meet the requirements of the furnace II class reliability, full-length steel after soaking and circumferential temperature difference ≤10 , the temperature in accordance with the set value of automatic or manual control, with temperature alarm function to ensure that the temperature is in the range of process requirements. Pipe heating time, stepping furnace heat treatment furnace belongs to the fast, low-alloy steel pipe maximum heating speed of up to 40 / min.
Optimum efficiency control of high frequency welded pipe in welding process
In most cases, optimized welding process, power loss can be reduced 50% and can improve the welding quality, reduce downtime, increase production.
Stress on the trench corrosion of high-frequency straight seam resistance welding pipe
Trench etching is generally believed that acute heat in the welding process, the results of local tissue metal and chemical change caused by quenching.
Technology of straight seam high frequency resistance welded steel pipe
Factors that affect the raw material for the steel pipe welding quality affect the quality of raw materials are mainly steel mechanical properties unstable surface defects and strip geometry deviation big three aspects, therefore, we should focus on these three aspects of control.
