Economic type diphasic stainless steel with good toughness and weldability and manufacturing method thereof

A technology of duplex stainless steel and weldability, which is applied in the field of economical duplex stainless steel and its manufacturing, can solve the problems of low-temperature toughness decline of welded joints, and achieve the effect of reducing the cost of raw materials

Inactive Publication Date: 2014-11-05
BAOSTEEL STAINLESS STEEL
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

However, due to the low content of N and Ni, the low temperatu

Method used

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  • Economic type diphasic stainless steel with good toughness and weldability and manufacturing method thereof
  • Economic type diphasic stainless steel with good toughness and weldability and manufacturing method thereof
  • Economic type diphasic stainless steel with good toughness and weldability and manufacturing method thereof

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Experimental program
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Embodiment 1

[0051] The metallographic structure of the alloy of embodiment 1 is as figure 1 shown. After the sample is ground and polished, electrolytic corrosion is performed, and the etchant is 40gKOH+100mlH 2 O, corrosion current 0.3~0.8A / cm 2 , and finally analyzed the proportion of austenite by quantitative metallographic method under metallographic microscope. In the figure, the black structure is ferrite, the white structure is austenite, and the austenite phase accounts for about 53%. The metallographic structure of embodiment 2 welding heat-affected zone is as figure 2 shown.

[0052] Table 1 Unit: % by weight

[0053]

[0054] Table 2

[0055]

[0056]

[0057] It can be seen from Table 1 and Table 2 that since the steel of the present invention uses Mn and N instead of Ni content, and contains no or only a small amount of alloying elements such as Mo and Cu, compared with 304 austenitic stainless steel, its alloy cost is significantly reduced. Compared with dup...

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Abstract

Disclosed are economic type diphasic stainless steel with good toughness and weldability and a manufacturing method thereof. The economic type diphasic stainless steel comprises the chemical components by the weight percentage: 0.01-0.05% of C, 0.2-1.0% of Si, 4.0-6.0% of Mn, 20.0-21.5% of Cr, 1.7-3.0% of Ni, 0.15-0.20% of N, not more than 0.5% of Mo, not more than 0.5% of W, not more than 0.5% of Cu, not more than 0.006% of B, and the balance Fe and inevitable impurities. The stainless steel mainly adopts 4.0-6.0% of Mn to replace Ni, at the same time, controls the contents of Mo and Cu in 0.5% or less, thereby significantly reducing alloy raw material costs; the content of Ni is controlled in 1.7-3.0%, the content of N is controlled in 0.15-0.2%, and the ferrite equivalent weight P[alpha] of a high-temperature heat affected zone is controlled in 20.5 or less, not only can the low temperature impact toughness of a parent metal be ensured, but also the good weldability can be obtained, and welded joints are allowed to have good low-temperature impact toughness. 304 austenitic stainless steel having the nickel content reaching up to 8% or more is replaced by the diphasic stainless steel under conditions of room temperature and low temperatures.

Description

technical field [0001] The invention relates to a duplex stainless steel and a manufacturing method thereof, in particular to an economical duplex stainless steel with excellent toughness and weldability and a manufacturing method thereof. Background technique [0002] Duplex stainless steel is composed of ferrite and austenite at room temperature, and the proportion of each phase is not less than 30%. Due to the existence of two-phase structure, duplex stainless steel has the characteristics of ferritic stainless steel and austenitic stainless steel. It is a kind of stainless steel with the best matching of high strength and high corrosion resistance. Compared with ferritic stainless steel, it has high toughness, low brittle transition temperature, intergranular corrosion resistance and significantly improved weldability, while retaining the advantages of high thermal conductivity and small expansion coefficient of ferritic steel. Compared with austenitic stainless steel, ...

Claims

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Application Information

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IPC IPC(8): C22C38/58
Inventor 胡锦程宋红梅杨宴宾张伟王治宇江来珠
Owner BAOSTEEL STAINLESS STEEL
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