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Method for preparing seamless steel tubes made of martensite precipitation hardening stainless steel

A technology of precipitation hardening and seamless steel pipes, which is applied in the direction of manufacturing tools, metal rolling, heat treatment equipment, etc., can solve the problems of longitudinal cracking on the surface of steel pipes, failure to form batch supply, and failure to produce products, etc., to achieve comprehensive mechanical properties Improvement, surface quality improvement, production efficiency improvement effect

Inactive Publication Date: 2009-12-30
BAOSTEEL SPECIAL STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the past, several 0Cr17Ni4Cu4Nb stainless steel seamless pipes were trial-produced. During the processing, the tools and dies were seriously worn out, and the mold cracks and longitudinal cracks on the steel pipe surface occurred many times, so subsequent processing could not be carried out.
And the pass rate of finished products is very low, about 20%. Due to various reasons, no products meeting the requirements of finished products were finally produced, and batch supply failed to form

Method used

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  • Method for preparing seamless steel tubes made of martensite precipitation hardening stainless steel
  • Method for preparing seamless steel tubes made of martensite precipitation hardening stainless steel
  • Method for preparing seamless steel tubes made of martensite precipitation hardening stainless steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1、2

[0025] In this example, 0Cr17Ni4Cu4Nb stainless steel is used, and its chemical composition weight percentage ratio is: C: 0.05, Si: 0.53, Mn: 0.43, S: 0.002, P: 0.022, Cr: 16.12, Cu: 3.28, Ni: 4.37, Nb: 0.26, Mo: 0.09, Ti: 0.01, W: 0.04, As: 0.01, Al: 0.01.

[0026] Heating after peeling and blanking of the tube blank: Φ80 tube blank is peeled to Φ75 through machining, and the specification of the tube blank is determined according to the finished product specification. If the outer diameter of the finished product is less than 60mm, the Φ80 tube blank can be selected; if the finished product outer diameter is greater than 60mm, the specification of the tube blank must be Greater than Φ80; heating temperature 1100°C-1150°C;

[0027] Hot piercing: tube blank heating process such as figure 1 As shown, the size of the blank tube is Φ80×7mm, the heating temperature is controlled by thermal perforation to 1120°C, and the holding time is greater than 30 minutes;

[0028] Cooling:...

Embodiment 3

[0047] In this example, 0Cr17Ni4Cu4Nb stainless steel is used, and its chemical composition weight percentage ratio is: C: 0.05, Si: 0.53, Mn: 0.43, S: 0.002, P: 0.022, Cr: 16.12, Cu: 3.28, Ni: 4.37, Nb: 0.26, Mo: 0.09, Ti: 0.01, W: 0.04, As: 0.01, Al: 0.01.

[0048] Heating after peeling and blanking of the tube blank: Φ90 tube blank is peeled to Φ85 through machining, and the peeled tube blank is heated in an inclined bottom furnace, and the heating temperature range is 1130°C-1150°C;

[0049] Hot piercing: tube blank heating process such as figure 2 As shown, the size of the blank tube is Φ90×8mm, the heating temperature is controlled by thermal perforation to 1130°C, and the holding time is greater than 30 minutes;

[0050] Cooling: After thermal perforation, the waste tubes are air-cooled by stacking;

[0051] Surface treatment of waste pipe: including finishing, pickling, lubrication, pickling after flattening the waste pipe, the pickling liquid formula is HF 5-8%, HN...

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Abstract

The invention discloses a method for preparing seamless steel tubes made of martensite precipitation hardening stainless steel, which comprises the following steps of billets, peeling, blanking, heating, hot punching, cooling, finishing, acid cleaning, lubricating, degreasing, heat treatment, straightening, tube cutting, acid cleaning, inspection, and packaging and warehousing. Compared with the prior art, the method has the following advantages that: pierced billets after hot punching are cooled in a pile so as to reduce working procedures and cost; the intermediate heat treatment adopts solution treatment, has short time and high efficiency, and improves surface quality; the tubes all adopt cold rolling process to improve yield; and vacuum aging treatment is adopted to improve the comprehensive mechanical property, the finished product inspection qualified rate reach 95 percent, and the yield from the billets to the finished products reach 51.31 percent.

Description

technical field [0001] The invention relates to a method for manufacturing metallurgical martensitic seamless steel pipes, in particular to the processing technology of martensitic precipitation hardening stainless steel from pipe blanks to finished pipes. Background technique [0002] Martensitic precipitation hardening stainless steel has high strength, good corrosion resistance, oxidation resistance and weldability. It is suitable for the manufacture of high-strength corrosion-resistant parts that work below 400 °C, such as fasteners for aircraft and missiles, front and rear mounting edges of engine turbine casings, turbine blades, valves, and structural casings. The main grades of this type of stainless steel are 0Cr17Ni4Cu4Nb, 0Cr17Ni7Al, 0Cr15Ni5Cu2Ti and so on. Among them, the typical grade 0Cr17Ni4Cu4Nb stainless steel standard chemical composition weight percentage ratio is: C: 0.07, Si: ≤1.00, Mn: ≤1.00, S: ≤0.030, P: ≤0.035, Cr: 15.50~17.50, Cu: 3.00~5.00, Ni: 3...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23P15/00B21B19/04C22C38/42C21D9/08C23G3/04
Inventor 蔡志刚孙纪涛邵卫东袁卫昌方静贤
Owner BAOSTEEL SPECIAL STEEL CO LTD
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