CN103143822A - Welding technology for super duplex stainless steel - Google Patents

Abstract

The invention discloses a welding technology for super duplex stainless steel, which is characterized in that the welding technology comprises the following steps that 1), backing manual argon tungsten-arc welding is conducted by adopting 99.99% inert argon shielding; 2), semiautomatic filling cosmetic welding is conducted by adopting 80% argon plus 20% carbon dioxide shielding; 3) a welding groove is processed; 4) the surface of a workpiece to be welded is cleaned and inspected; and 5) submerged-arc welding of common duplex stainless steel is conducted. According to the welding technology, the welding of the common duplex stainless steel can ensure that a chemical composition of a welding seam meets a standard specification requirement; a ferrite content of a welding joint (including the welding seam and a heat-affected zone) is controlled to be 30-65%; and the welding joint has a good mechanical property and spot corrosion resistance.

Description

A kind of super-duplex stainless steel welding procedure

Technical field

The present invention relates to stainless steel and make the field, the welding procedure of especially welding about a kind of two phase stainless steel.

Background technology

The comprehensive mechanical property of two phase stainless steel tubing is excellent, has higher intensity and fatigue strength, and its yield strength is the twice of 18-8 steel; In the operating mode of chlorion high concentration, as having good anti-pitting/anti-corrosion at a seam/stress corrosion resistant ability in high temperature seawater/high-temperature chlorine compound solution; Its welding region hot cracking tendency is less, and solderability is good.two-way stainless steel at 20 century 70s by the exploitation of SUMITOMO CHEMICAL metal industry company, the characteristics of this steel grade are at Gao Ge, add tungsten on the basis of molybdenum, the elements such as copper are in order to improve the slit and corrosion resistant performance of steel, be adapted to hot sea water, the ambient conditions such as bittern water, compare with 300 series austenitic stainless steel, has high strength, good plasticity and formability, outstanding local corrosion performance is arranged, it is the material of an anti-Neutral Chloride compound local corrosion, included the ASTM standard in, the A790 standard, and list the UNS standard in the S31260 trade mark, and successfully be applied on the parts such as seawater heat exchange and hot bittern water axial-flow pump.Due to the metallurgy characteristic of two phase stainless steel weldering self, the performance in order to guarantee that it is good during welding adopts this efficient welding method of submerged-arc welding to be applied to the two phase stainless steel weldering all the time and also exists technical problem.

Summary of the invention

For above problem, the object of the present invention is to provide a kind of super-duplex stainless steel welding procedure, be the submerged-arc welding of adopting high-performance, realized the two phase stainless steel efficient welding.

Technical scheme of the present invention is achieved in the following ways: a kind of super-duplex stainless steel welding procedure is characterized in that: comprise the steps:

1), adopt 99.99% argon gas inert gas shielding, carry out GTAW bottoming welding;

2), adopt 80% argon gas to add 20% and CO 2 gas-shieldedly carry out semi-automatic filling cover welding;

3), bevel for welding processing;

4), the cleaning of surface of the work to be welded and inspection;

5), the stainless submerged arc welding of common two-phase.

The present invention, the common double of carrying out can guarantee that to stainless welding the chemical analysis of weld seam meets that standard criterion requires, the ferrite content of welding point (comprising Seam and heat effected zone) is controlled between 30-65%, and welding point has good mechanical property and pitting corrosion performance.Weld properties: 〥 b/Mpa 〉=650, 〥 0.2/Mpa 〉=450, δ 5/% 〉=25, Ak/J 〉=150, HRC～20.

The specific embodiment

A kind of super-duplex stainless steel welding procedure comprises the steps:

1, adopt 99.99% argon gas inert gas shielding, carry out GTAW bottoming welding.

2, adopt 80% argon gas to add 20% and CO 2 gas-shieldedly carry out semi-automatic filling cover welding.

3, bevel for welding processing.

4, the cleaning of surface of the work to be welded and inspection.

5, the stainless submerged arc welding of common two-phase.

The present invention can obtain the metallographic structure of ferrite and austenite ratio relative equilibrium when soldering diphasic stainless steel, ferrite content is between 45-65% after measured; The mechanical performance of welding point and corrosion resistance can fully be guaranteed, and its tensile strength is about 640 newton/square millimeter after measured, and hardness number is between 220-280HV10.Use carbon dioxide+nitrogen mixture body to do protective gas, can reduce spatter, appearance of weld is attractive in appearance.

Claims (1)

1. a super-duplex stainless steel welding procedure, is characterized in that: comprise the steps:

1), adopt 99.99% argon gas inert gas shielding, carry out GTAW bottoming welding;

2), adopt 80% argon gas to add 20% and CO 2 gas-shieldedly carry out semi-automatic filling cover welding;

3), bevel for welding processing;

4), the cleaning of surface of the work to be welded and inspection;

5), the stainless submerged arc welding of common two-phase.