CN102145423A - Argon arc welding surfacing process for cobalt-free material ERFeCr-A5 - Google Patents

Abstract

The invention relates to the technical field of welding, in particular to an argon arc welding surfacing process for a cobalt-free material ERFeCr-A5, comprising the following steps of: (1) preparing and cleaning before welding: preheating a workpiece to 100-250 DEG C; (2) welding: carrying out argon arc welding, wherein the welding current is direct current, the polarity is anode, the current range is 190-210A, the protective gas is argon gas, the flow rate of the argon gas is 11-15L/min, and the welding speed is 9-11cm/min; and (3) postheat treatment: preserving the heat of the workpiece at 100-250 DEG C for more than 4 hours. The invention aims to provide a reasonable argon arc welding surfacing process for the cobalt-free material ERFeCr-A5 to meet the requirement of a production process of a cobalt-free hard alloy surfacing layer on a sealing surface of a nuclear safety class valve.

Description

Cobalt-less material ERFeCr-A5 argon arc-welding built-up welding technology

Technical field

The present invention relates to welding technology field, relate to a kind of cobalt-less material ERFeCr-A5 argon arc-welding built-up welding technology concretely.

Background technology

Because the reactor-loop coolant system is for the restriction of cobalt content, must select the wlding of no cobalt for use, one of them is the ERFeCr-A5 wlding, contain chromium carbide in this weld metal, therefore have very high hardness and wearability, and have the favorable mechanical processing characteristics, but the sealing surface with this material built-up welding is very easy to cracking, the welding difficulty is bigger, so that product percent of pass is very low, has a strong impact on production.

Summary of the invention

Defective in view of prior art exists the purpose of this invention is to provide a kind of rational cobalt-less material ERFeCr-A5 argon arc-welding built-up welding technology, to satisfy the needs of nuclear grade valve sealing surface cobalt-free hard alloy overlay cladding production technology.

The technical solution adopted for the present invention to solve the technical problems is: cobalt-less material ERFeCr-A5 argon arc-welding built-up welding technology, and the step of described cobalt-less material ERFeCr-A5 argon arc-welding built-up welding technology is as follows:

1) welds preceding the preparation and preweld cleaning; Workpiece is carried out preheating, be preheating to 100～250 ℃;

2) welding: adopt argon arc welding, welding current is a direct current, and polarity is for just connecing, and scope is 190～210A; Protective gas is an argon gas, and its flow is 11～15L/min; Speed of welding is 9～11cm/min;

3) after-baking: down be incubated 4 hour or more at 100～250 ℃ workpiece.

The invention has the beneficial effects as follows: utilize cobalt-less material ERFeCr-A5 argon arc-welding built-up welding technology provided by the present invention that welding work pieces is carried out procedure qualification, postwelding does not have any crackle, and is functional, qualified fully.This process application is in production, and product percent of pass reaches more than 95%.Be applied on the overlay cladding of valve sealing face,, prove that it satisfies standard and working condition requirement fully through the test of cold and hot state operating life, end load test etc.

Description of drawings

Fig. 1 is a valve body hardfacing schematic diagram;

Fig. 2 is a flap hardfacing schematic diagram;

Reference numeral is as follows: 1, built-up welding sealing surface I, 2, built-up welding sealing surface II.

The specific embodiment

Specific embodiment:

Use the flap and the valve body sealing surface of the 1 〞 Y type bellows stop valve that uses in the ERFeCr-A5 wlding welding AP1000 nuclear power station.

The material of the valve body (see figure 1) of stop valve is steel alloy SA105M, and the material of sealing surface is ERFeCr-A5, and the welding gimmick adopts argon arc-welding built-up welding (GTAW), joint form is built-up welding, adopting diameter is the welding wire of Φ 3.2 mm, and overlay cladding thickness is 5mm, and the built-up welding number of plies is 2 layers; Preheat temperature is 100～150 ℃; the flow of argon shield gas is 12 L/min; purity of argon 99.999%; jet size is Φ 12mm; direct current is 200A, and polarity is positive polarity, speed of welding 9～11cm/min; the holding temperature of after heat is that 150 ℃, temperature retention time are 4 hours, and the method for cleaning of welding bead is for brushing.

The flap (see figure 2) material of stop valve is special steel (A565-616); the material of sealing surface is ERFeCr-A5; the welding gimmick is for adopting argon arc-welding built-up welding (GTAW), and joint form is built-up welding, and adopting diameter is the welding wire of Φ 3.2 mm; layer thickness is 5mm; the built-up welding number of plies is 2 layers, and preheat temperature is 210～250 ℃, and the flow of argon shield gas is 12 L/min; purity of argon 99.999%; jet size is Φ 12mm, and direct current is 200A, and polarity is positive polarity; speed of welding 9～11cm/min; 150 ℃ of the holding temperatures of after heat, temperature retention time are 4 hours, and the method for cleaning of welding bead is for brushing; postwelding stress-removal treatment temperature is 630 ℃, and temperature retention time is 35 minutes.

Claims (1)

1. cobalt-less material ERFeCr-A5 argon arc-welding built-up welding technology, it is characterized in that: the step of described cobalt-less material ErFeCr-A5 argon arc-welding built-up welding technology is as follows:

1) welds preceding the preparation and preweld cleaning; Workpiece is carried out preheating, be preheating to 100～250 ℃;

2) welding: adopt argon arc welding, welding current is a direct current, and polarity is for just connecing, and scope is 190～210A; Protective gas is an argon gas, and its flow is 11～15L/min; Speed of welding is 9～11cm/min;

3) after-baking: down be incubated 4 hour or more at 100～250 ℃ workpiece.

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