CN105671298A - Heat treatment technique for weld crater of alloy small-diameter pipeline - Google Patents

Abstract

The invention discloses a heat treatment technique for a weld crater of an alloy small-diameter pipeline. The heat treatment technique comprises the following steps of construction preparation, bottoming and preheating, electrowelding preheating, post-weld treatment and hardness detection. The heat treatment technique specifically comprises the steps that (1) oxygen flames and acetylene gas flames are used for preheating; (2) welding is conducted, and the interlayer temperature is supposed to be kept not lower than 250 DEG C and not higher than 400 DEG C in the welding process; and (3) post-weld heat treatment is conducted. According to the heat treatment technique, working procedures are arranged reasonably and harmonically, the rejection rate can be decreased effectively, and the product quality is high.

Description

A kind of alloy pipeline path weld bond Technology for Heating Processing

Technical field

The present invention relates to alloy pipeline path weld bond Technology for Heating Processing.

Background technology

There is processing step phenomenon inharmonious, irrational in existing alloy pipeline path weld bond Technology for Heating Processing, produce sometimes to repeat to process or excess processes, have a strong impact on product quality, and percent defective is higher, employee's operant skill is required higher, causes product cost higher.

Additionally existing alloy pipeline path weld bond Technology for Heating Processing processing step is tediously long, and the distribution of each operation exists many irrational places.

Summary of the invention

In order to realize the purpose of the present invention, the present invention provides the alloy pipeline path weld bond Technology for Heating Processing that a kind of procedure arrangement is reasonable, coordinate.

For solving above-mentioned technical problem, the present invention adopts the following technical scheme that

A kind of alloy pipeline path weld bond Technology for Heating Processing, comprises the steps:

Preparation of construction → bottoming preheating → electric welding preheating → after welding treatment → Hardness Surveillance;

1), preheat with oxygen, acetylene gas flame;

1.1), during heating, generally by oxygen gauge top to 3-4Mpa, by Acetylene gauge top to 0.05-0.1Mpa, can adjust again as required;

1.2) heating process must ensure homogeneous temperature, thermometric at any time; Heat time heating time is about 3-5 minute;

1.3) when temperature is raised to the preheating temperature of requirement, and when temperature is substantially uniform, namely notify that welder starts welding;

2) welding, in welding process, should keep interlayer temperature to be not less than 250 DEG C, and not higher than 400 DEG C;

3), post weld heat treatment

3.1) thermocouple is arranged in welding pipe welding seam edge;

3.2) when carrying out heat treatment, heater dedicated being fixed on weld bond by supporting with tubing specification, heater and tube wall are close to;

3.3), after heater power lead all connects, answer detailed inspection with or without short circuit phenomenon, the lead-in wire of heater, thermocouple compensating wire whether touch on heater, whether connection correct, confirm errorless after can power transmission heating;

3.4) temperature starts to calculate constant temperature time when rising to heating-up temperature; In temperature-fall period, as excessively slow in cooling rate (comparing with warming and cooling rate setting value), heat-preservation cotton thickness can be reduced to improve cooling rate; No longer control cooling rate when temperature is down to below 300 DEG C, power supply should be closed, make welding point natural cooling;

3.5), before weld bond preheating, pipe to be blocked, forbid to wear thorax wind in pipe;

3.6) weld bond in heat treatment process must not stress, the fixing device of welding should pending complete could be removed;

3.7) heat treated overall process should continuously perform, and should not interrupt; Power-off as unexpected in fault, when answering power transmission to be restored, heats up again by normal programming rate, and temperature when rising to power-off opens autographic apparatus; When burning out such as heater, answering slow cooling to lower the temperature, then again wrap up, power transmission processes again.

Procedure arrangement of the present invention is reasonable, coordination, it is possible to be effectively reduced percent defective and product quality is high.

Detailed description of the invention

Below in conjunction with embodiment, the invention will be further described:

A kind of alloy pipeline path weld bond Technology for Heating Processing, comprises the steps:

Preparation of construction → bottoming preheating → electric welding preheating → after welding treatment → Hardness Surveillance;

1), preheat with oxygen, acetylene gas flame;

1.1), during heating, generally by oxygen gauge top to 3-4Mpa, by Acetylene gauge top to 0.05-0.1Mpa, can adjust again as required;

1.2) heating process must ensure homogeneous temperature, thermometric at any time; Heat time heating time is about 3-5 minute;

1.3) when temperature is raised to the preheating temperature of requirement, and when temperature is substantially uniform, namely notify that welder starts welding;

2) welding, in welding process, should keep interlayer temperature to be not less than 250 DEG C, and not higher than 400 DEG C;

3), post weld heat treatment

3.1) thermocouple is arranged in welding pipe welding seam edge;

3.2) when carrying out heat treatment, heater dedicated being fixed on weld bond by supporting with tubing specification, heater and tube wall are close to;

3.3), after heater power lead all connects, answer detailed inspection with or without short circuit phenomenon, the lead-in wire of heater, thermocouple compensating wire whether touch on heater, whether connection correct, confirm errorless after can power transmission heating;

3.4) temperature starts to calculate constant temperature time when rising to heating-up temperature; In temperature-fall period, as excessively slow in cooling rate (comparing with warming and cooling rate setting value), heat-preservation cotton thickness can be reduced to improve cooling rate; No longer control cooling rate when temperature is down to below 300 DEG C, power supply should be closed, make welding point natural cooling;

3.5), before weld bond preheating, pipe to be blocked, forbid to wear thorax wind in pipe;

3.6) weld bond in heat treatment process must not stress, the fixing device of welding should pending complete could be removed;

3.7) heat treated overall process should continuously perform, and should not interrupt; Power-off as unexpected in fault, when answering power transmission to be restored, heats up again by normal programming rate, and temperature when rising to power-off opens autographic apparatus; When burning out such as heater, answering slow cooling to lower the temperature, then again wrap up, power transmission processes again.

Claims (1)

1. an alloy pipeline path weld bond Technology for Heating Processing, is characterized in that: comprise the steps:

Preparation of construction → bottoming preheating → electric welding preheating → after welding treatment → Hardness Surveillance;

1), preheat with oxygen, acetylene gas flame;

1.1), during heating, generally by oxygen gauge top to 3-4Mpa, by Acetylene gauge top to 0.05-0.1Mpa, can adjust again as required;

1.2) heating process must ensure homogeneous temperature, thermometric at any time; Heat time heating time is about 3-5 minute;

1.3) when temperature is raised to the preheating temperature of requirement, and when temperature is substantially uniform, namely notify that welder starts welding;

2) welding, in welding process, should keep interlayer temperature to be not less than 250 DEG C, and not higher than 400 DEG C;

3), post weld heat treatment

3.1) thermocouple is arranged in welding pipe welding seam edge;

3.2) when carrying out heat treatment, heater dedicated being fixed on weld bond by supporting with tubing specification, heater and tube wall are close to;

3.3), after heater power lead all connects, answer detailed inspection with or without short circuit phenomenon, the lead-in wire of heater, thermocouple compensating wire whether touch on heater, whether connection correct, confirm errorless after can power transmission heating;

3.4) temperature starts to calculate constant temperature time when rising to heating-up temperature;In temperature-fall period, as excessively slow in cooling rate (comparing with warming and cooling rate setting value), heat-preservation cotton thickness can be reduced to improve cooling rate; No longer control cooling rate when temperature is down to below 300 DEG C, power supply should be closed, make welding point natural cooling;

3.5), before weld bond preheating, pipe to be blocked, forbid to wear thorax wind in pipe;

3.6) weld bond in heat treatment process must not stress, the fixing device of welding should pending complete could be removed;

3.7) heat treated overall process should continuously perform, and should not interrupt; Power-off as unexpected in fault, when answering power transmission to be restored, heats up again by normal programming rate, and temperature when rising to power-off opens autographic apparatus; When burning out such as heater, answering slow cooling to lower the temperature, then again wrap up, power transmission processes again.