A method of manufacturing a seamless steel pipe

A manufacturing method and technology of seamless steel pipes, applied in the field of seamless steel pipes, can solve the problems of casualty accidents, property loss, low strength, cylinder explosion, etc., and achieve the effects of ensuring quality and structural strength, good welding performance, and ensuring uniformity

Active Publication Date: 2017-03-15
SHANDONG MOLONG PETROLEUM MACHINERY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the embodiments of the present invention is to provide a method for manufacturing seamless steel pipes, which aims to solve the problem of severe accidents such as fracture and cylinder explosion due to low strength and poor toughness when the seamless steel pipes manufactured in the prior art are used in hydraulic cylinders , causing major casualties and property damage

Method used

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  • A method of manufacturing a seamless steel pipe

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0058] The steps of the present embodiment are the same as those described above, and the proportioning of alloying elements is:

[0059] Carbon: 0.19%; Silicon: 0.30%; Manganese: 1.21%; Phosphorus: 0.009%; Sulfur: 0.01%; Chromium: 0.021%; Copper: 0.039%; Aluminum: 0.025%; Carbon equivalent: 0.41%; the rest is molten steel.

Embodiment 2

[0061] This embodiment is the same as Embodiment 1, and the difference lies in the proportioning of alloying elements. The proportioning of alloying elements in this embodiment is:

[0062] Carbon: 0.17%; Silicon: 0.28%; Manganese: 1.07%; Phosphorus: 0.009%; Sulfur: 0.011%; Chromium: 0.022%; Copper: 0.038%; Aluminum: 0.015%; Carbon equivalent: 0.37%; the rest is molten steel.

Embodiment 3

[0064] This embodiment is the same as Embodiment 1, and the difference lies in the proportioning of alloying elements. The proportioning of alloying elements in this embodiment is:

[0065] Carbon: 0.15%; Silicon: 0.27%; Manganese: 0.98%; Phosphorus: 0.009%; Sulfur: 0.011%; Chromium: 0.022%; Copper: 0.038%; Aluminum: 0.015%; Carbon equivalent: 0.33%; the rest is molten steel.

[0066] The performance indicators achieved by the three embodiments are shown in Table 1:

[0067] Table I

[0068]

[0069] It can be seen from the performance indicators in Table 1 that:

[0070] Among them, the tensile property of the seamless steel pipe produced in Example 1 is the highest, the tensile property of the seamless steel tube produced in Example 3 is at the lower limit of design requirements, and the tensile property of the seamless steel tube produced in Example 2 is at the lower limit of the implementation. Between example one and example three.

[0071] At the same time, a comp...

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Abstract

The invention discloses a manufacturing method of a seamless steel pipe. The manufacturing method comprises the following steps of making steel: feeding a SiCaBa alloy core wire after slagging molten steel in a steel ladle, and expanding slag to form foamed slag; adjusting the amount, the alkalinity and the fluidity of the slag according to slag conditions, and adding SiC powder, silicon calcium (barium), silicon iron and calcium carbide so as to reduce refined slag to form white slag; adding 0.13-0.20% of carbon, 0.25-0.50% of silicon, 0.9-1.3% of manganese, less than or equal to 0.030% of phosphorus, less than or equal to 0.030% of sulphur, 0.03-0.10% of vanadium, 0.015-0.040% of aluminium, less than or equal to 0.20% of chromium, less than or equal to 0.10% of nickel, less than or equal to 0.10% of molybdenum, less than or equal to 0.10% of titanium, and less than or equal to 0.20% of copper; pouring out a part of the refined slag, and retaining a slag layer, the molten steel surface layer of which is less than or equal to 100 mm; stirring in vacuum; feeding an aluminium wire with the diameter of 12 mm after breaking vacuum; feeding a pure calcium wire for modifying inclusions; blowing by using argon so that the molten steel is uniform; continuously casting; rolling; thermally treating; straightening; and detecting flaws. The seamless steel pipe prepared by the invention has high strength, high toughness, low carbon equivalent and good welding property, and therefore, the use reliability and the safety are increased.

Description

technical field [0001] The invention belongs to the technical field of seamless steel pipes, in particular to a method for manufacturing seamless steel pipes. Background technique [0002] At this stage, the seamless steel pipes used in the hydraulic cylinders for the front roof of automobiles are generally: 27SiMn seamless steel pipes and No. 45 steel seamless steel pipes. The hydraulic oil cylinder processed by the manufacturing method has low strength, poor toughness, large stress in the cylinder body, and poor welding performance. Thereby hydraulic oil cylinder is in use process, often takes place in the malignant accident such as fracture, frequent explosion cylinder in welding treatment place, and then causes heavy casualty accident and property loss. Contents of the invention [0003] The purpose of the embodiments of the present invention is to provide a method for manufacturing seamless steel pipes, which aims to solve the problem of severe accidents such as frac...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/50C21D8/10
Inventor 张云三国焕然藏中山黎新春孙晶张录天张增江
Owner SHANDONG MOLONG PETROLEUM MACHINERY
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