CN105714095A - Postweld heat treatment process - Google Patents

Abstract

The invention discloses a postweld heat treatment process. The postweld heat treatment process comprises the following steps: 1) employment of a postweld heat treatment process, wherein 1.2) for butt welding, the nominal thickness of a welding part should be the nominal thickness of a welding part directly butts against a welding zone, 1.3) except regulations in a drawing or corresponding design document, the heating and cooling rates of heat treatment are calculated by the unit DEG C/h, 200 DEG C/h is taken as the heating rate if a calculated result exceeds 200 DEG C/h, and 100 DEG C/h is taken as the cooling rate if a calculated result is lower than 100 DEG C/h, and 1.4) except regulations in the drawing or corresponding design document, controlling may not be carried out if temperature is lower than 300 DEG C during cooling and self-cooling along with a heating furnace is carried out; 2) installation of a thermocouple; 3) installation of a heater; and 4) installation of a heat-insulation layer. The process provided by the invention is reasonable in procedure and low in manufacturing cost.

Description

A kind of post weld heat treatment technique

Technical field

The present invention relates to a kind of post weld heat treatment technique.

Background technology

Existing post weld heat treatment technique exists that procedure arrangement is unreasonable, operation is various, operator's skill requirement is higher so that production cost is higher.

Summary of the invention

Because the drawbacks described above of prior art, the technical problem to be solved be to provide a kind of operation rationally, the post weld heat treatment technique of low cost of manufacture.

For achieving the above object, the invention provides

A kind of post weld heat treatment technique, comprises the steps:

1), post weld heat treatment technique

1.1) when adopting arc welding method welding, can according to by the weldering part mother metal trade mark and thickness, according to the form below determines post weld heat treatment specification；

Note: if specification of heat treatment is had regulation by drawing or respective design file, then perform the regulation in drawing or respective design file；

1.2) for butt welding, as the nominal thickness of soldering part, it is necessary to be the nominal thickness of the soldering part that directly against weld metal zone；

1.3) except drawing or respective design file have regulation, in heat treatment process, warming and cooling rate calculates by (DEG C/h), and the result calculated is as, during more than 200 DEG C/h, namely taken 200 DEG C/h, the result calculated is as, during lower than 100 DEG C/h, namely taken 100 DEG C/h；

1.4), except having regulation in drawing or respective design file, in temperature-fall period, temperature can not control below 300 DEG C, carries out self cooling with heating furnace；

2), thermocouple is installed

2.1) the hot junction point of thermocouple should be directly installed on weld seam or be arranged within the scope of weld seam 30mm；

2.2) the fixing employing by crimping of thermocouple is fixed, and the fixing point of every thermocouple at least should have two places；

3), mounting heater

3.1) heater of different size and shape is rationally selected according to workpiece shapes, it is ensured that processed weld seam can be covered by heater in prescribed limit；

3.2) uniform width of heating during post weld heat treatment should cannot be less than 3 times of throat depths in the every side of axis of a weld, and is not less than 60mm；

3.3) under individual cases, when the architectural characteristic of parts itself is it cannot be guaranteed that during width required by heating tape, then width of heating when allowing post weld heat treatment reduces 20%, but must be increased by 1 hour by constant temperature time simultaneously；

4), heat-insulation layer is installed

4.1) heat-insulation layer adopts ceramic fibre, and the thickness of heat-insulation layer is not less than 40mm；

4.2) heat treated insulation width is counted from Weld pipe mill, and every side cannot be less than 5 times of mother metal thickness, and is greater than heater edge 200～250mm；

4.3) heat-insulation layer iron wire carries out colligation, it is ensured that heat-preservation cotton is close to heat block；Heat treatment to special installation weld seam, can be welded hook nail in advance and fix heat-insulation layer.

The invention has the beneficial effects as follows: operation of the present invention is reasonable, low cost of manufacture.

Detailed description of the invention

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

A kind of post weld heat treatment technique, comprises the steps:

1), post weld heat treatment technique

1.1) when adopting arc welding method welding, can according to by the weldering part mother metal trade mark and thickness, according to the form below determines post weld heat treatment specification；

Note: if specification of heat treatment is had regulation by drawing or respective design file, then perform the regulation in drawing or respective design file；

1.2) for butt welding, as the nominal thickness of soldering part, it is necessary to be the nominal thickness of the soldering part that directly against weld metal zone；

1.3) except drawing or respective design file have regulation, in heat treatment process, warming and cooling rate calculates by (DEG C/h), and the result calculated is as, during more than 200 DEG C/h, namely taken 200 DEG C/h, the result calculated is as, during lower than 100 DEG C/h, namely taken 100 DEG C/h；

1.4), except having regulation in drawing or respective design file, in temperature-fall period, temperature can not control below 300 DEG C, carries out self cooling with heating furnace；

2), thermocouple is installed

2.1) the hot junction point of thermocouple should be directly installed on weld seam or be arranged within the scope of weld seam 30mm；

2.2) the fixing employing by crimping of thermocouple is fixed, and the fixing point of every thermocouple at least should have two places；

3), mounting heater

3.1) heater of different size and shape is rationally selected according to workpiece shapes, it is ensured that processed weld seam can be covered by heater in prescribed limit；

3.2) uniform width of heating during post weld heat treatment should cannot be less than 3 times of throat depths in the every side of axis of a weld, and is not less than 60mm；

3.3) under individual cases, when the architectural characteristic of parts itself is it cannot be guaranteed that during width required by heating tape, then width of heating when allowing post weld heat treatment reduces 20%, but must be increased by 1 hour by constant temperature time simultaneously；

4), heat-insulation layer is installed

4.1) heat-insulation layer adopts ceramic fibre, and the thickness of heat-insulation layer is not less than 40mm；

4.2) heat treated insulation width is counted from Weld pipe mill, and every side cannot be less than 5 times of mother metal thickness, and is greater than heater edge 200～250mm；

4.3) heat-insulation layer iron wire carries out colligation, it is ensured that heat-preservation cotton is close to heat block；Heat treatment to special installation weld seam, can be welded hook nail in advance and fix heat-insulation layer.

Claims (1)

1. a post weld heat treatment technique, is characterized in that: comprise the steps:

1), post weld heat treatment technique

1.1) when adopting arc welding method welding, can according to by the weldering part mother metal trade mark and thickness, according to the form below determines post weld heat treatment specification；

Note: if specification of heat treatment is had regulation by drawing or respective design file, then perform the regulation in drawing or respective design file；

1.2) for butt welding, as the nominal thickness of soldering part, it is necessary to be the nominal thickness of the soldering part that directly against weld metal zone；

1.3) except drawing or respective design file have regulation, in heat treatment process, warming and cooling rate calculates by (DEG C/h), and the result calculated is as, during more than 200 DEG C/h, namely taken 200 DEG C/h, the result calculated is as, during lower than 100 DEG C/h, namely taken 100 DEG C/h；

1.4), except having regulation in drawing or respective design file, in temperature-fall period, temperature can not control below 300 DEG C, carries out self cooling with heating furnace；

2), thermocouple is installed

2.1) the hot junction point of thermocouple should be directly installed on weld seam or be arranged within the scope of weld seam 30mm；

2.2) the fixing employing by crimping of thermocouple is fixed, and the fixing point of every thermocouple at least should have two places；

3), mounting heater

3.1) heater of different size and shape is rationally selected according to workpiece shapes, it is ensured that processed weld seam can be covered by heater in prescribed limit；

3.2) uniform width of heating during post weld heat treatment should cannot be less than 3 times of throat depths in the every side of axis of a weld, and is not less than 60mm；

3.3) under individual cases, when the architectural characteristic of parts itself is it cannot be guaranteed that during width required by heating tape, then width of heating when allowing post weld heat treatment reduces 20%, but must be increased by 1 hour by constant temperature time simultaneously；

4), heat-insulation layer is installed

4.1) heat-insulation layer adopts ceramic fibre, and the thickness of heat-insulation layer is not less than 40mm；

4.2) heat treated insulation width is counted from Weld pipe mill, and every side cannot be less than 5 times of mother metal thickness, and is greater than heater edge 200～250mm；

4.3) heat-insulation layer iron wire carries out colligation, it is ensured that heat-preservation cotton is close to heat block；Heat treatment to special installation weld seam, can be welded hook nail in advance and fix heat-insulation layer.