阅读说明：本技术 一种双金属复合无缝钢管的冷轧制管方法 (Cold rolling pipe manufacturing method for bimetal composite seamless steel pipe ) 是由 陆江帆 倪建平 于 2018-05-31 设计创作，主要内容包括：本发明的一种双金属复合无缝钢管的冷轧制管方法,包括S31803双相不锈钢无缝钢管和GR2纯钛无缝钢管,本发明实现了S31803与GR2两种组元金属制成双层复合无缝钢管的工业化生产,在确保冷轧加工质量符合技术要求的的基础上,减少生产工序成本、降低操作难度,满足高端双层复合无缝钢管的冷轧生产需求。工艺合理、措施到位、便于现场生产组织,流程受控,安全可靠、实用高效,轧制的双层复合无缝钢管质量符合技术要求,对其他类似双金属复合无缝钢管的冷轧制管方法的应用于实践,具有一定的借鉴、应用价值。(The invention discloses a cold rolling method for a bimetal composite seamless steel tube, which comprises an S31803 duplex stainless steel seamless steel tube and a GR2 pure titanium seamless steel tube, realizes the industrial production of the double-layer composite seamless steel tube made of two component metals of S31803 and GR2, reduces the production process cost and the operation difficulty on the basis of ensuring that the cold rolling processing quality meets the technical requirements, and meets the cold rolling production requirement of the high-end double-layer composite seamless steel tube. The process is reasonable, measures are in place, the on-site production organization is convenient, the process is controlled, the method is safe, reliable, practical and efficient, the quality of the rolled double-layer composite seamless steel tube meets the technical requirements, and the method has certain reference and application values for the practice of other cold rolling methods similar to the bimetal composite seamless steel tube.)

1. A cold rolling method for a bimetal composite seamless steel tube comprises an S31803 duplex stainless steel seamless steel tube (1) and a GR2 pure titanium seamless steel tube (2), and comprises the following specific steps:

1) firstly, selecting specifications of inner and outer layers of metal, and selecting a composite pipe phi 25 x 3 as a manufacturing standard;

2) Firstly rolling an S31803 duplex stainless steel seamless steel pipe (1) according to a cold rolling conventional process, wherein the specification is phi 27 x 2.5mm, the inner diameter is phi 22mm, and the length is 5.0 m;

3) Then, the GR2 pure titanium seamless steel tube (2) is rolled according to the cold rolling conventional process, the specification is phi 21.5 x 1.0mm, wherein, the tolerance range of the outer diameter is plus or minus 0.1mm, the inner diameter is phi 19.5mm, the tolerance range of the inner diameter is plus or minus 0.1mm, the wall thickness is 1.0mm, the tolerance range of the wall thickness is plus or minus 0.05mm, the length is 5.0m, and the tolerance range of the length is plus or minus 0.2 mm;

4) sleeving the S31803 duplex stainless steel seamless steel pipe (1) and the GR2 pure titanium seamless steel pipe (2), wherein the S31803 duplex stainless steel seamless steel pipe is sleeved outside the GR2 pure titanium seamless steel pipe to form a bimetal composite pipe, and the sleeving gap of the bimetal composite pipe is controlled to be 0.40-0.60 mm;

5) rolling the bimetal composite pipe by using a three-roller periodic cold pilger mill, wherein the clearance value after the nesting in the step 4) is controlled to be 0.4-0.6 mm, and the bimetal composite pipe is rolled into S31803 and GR2 bimetal composite pipes with the specification of phi 25 x 3 x 6000mm according to the incoming material specification phi 27 x 3.5 x 5000mm, and the process of the step is characterized in that:

5.1) the rolling speed of the cold pilger mill is 30-80 times/minute, the rolling speed of the joint parts of the front and the rear tube blanks is reduced to 30-40 times, and the rolling force is 25-35 tons;

5.2) the length of a core rod of the cold-rolling pipe mill is 520-540 mm, and the straightness error of the core rod, namely the bending degree is less than or equal to 0.2mm per meter, so that good straightness derivation of the cold-rolling composite pipe is ensured;

5.3) the rolling feed of the cold pilger mill is 2-4 mm/time, while the feed during rolling at the joint parts of the front and rear tube blanks is slowed down to 2-2.5 mm/time, thereby offsetting the rod-dropping difficulty caused by the increase of the length of the mandrel and ensuring the inner surface quality and the straightness requirement of the composite tube;

6) degreasing the inner surface and the outer surface of the rolled bimetal composite seamless steel pipe in the step 5), specifically, degreasing the inner surface and the outer surface of the rolled bimetal composite seamless steel pipe by adopting a secondary degreasing process according to a GR2 titanium alloy degreasing process, adopting a conventional degreasing medium at the temperature of 40-60 ℃, and performing treatment and soaking for 0.5-1 min, sealing two ends of the bimetal composite seamless steel pipe by using a plastic plug after the quality requirement of the inner surface of the composite pipe is met, degreasing the bimetal composite seamless steel pipe by adopting an S31803 super duplex stainless steel degreasing process, adopting a conventional degreasing medium at the temperature of 60-80 ℃, and performing treatment and soaking for 10-15 min to meet the quality requirement of the outer surface of the composite pipe;

7) performing fixed cutting on the bimetal composite seamless steel pipe, specifically, performing end face fixed cutting processing on the bimetal composite seamless steel pipe subjected to deoiling treatment in the step 6) by adopting a metal band saw according to the length specified in the technical requirement;

8) the method comprises the following steps of (1) inspecting the bimetal composite seamless steel pipe, specifically, carrying out nondestructive inspection on the bimetal composite seamless steel pipe according to the specification of technical requirements;

9) And (3) after the steps 1) to 8) are finished, manufacturing the bimetal composite seamless steel pipe of S31803 and GR2, and obtaining a product meeting the technical quality requirement.

Technical Field

the invention relates to the field of cold-rolled tube processing of seamless steel tubes in the industries of metallurgy, machinery and the like, in particular to a cold-rolled tube processing method of a composite seamless steel tube consisting of S31803 and GR 2.

background

The seamless steel pipe is a common metallurgical and steel product, the bimetal seamless steel pipe is a high-end seamless steel pipe which is developed and produced in recent years and has high technical content and high added value, the seamless steel pipe is a composite seamless steel pipe consisting of two metal seamless steel pipes made of different materials, the bimetal seamless steel pipe has the excellent performances of two metals, and can obtain the comprehensive performances of high strength, corrosion resistance and the like, so the bimetal composite seamless steel pipe can play the role that the single metal seamless steel pipe cannot play easily in certain special environments, and has wide application prospect in the industries of petroleum, chemical engineering, nuclear power and the like.

Disclosure of Invention

In order to solve the problems, the invention provides a cold rolling method of a bimetal composite seamless steel tube by exploring and practicing a cold rolling production process method of an S31803 and GR2 double-layer composite seamless steel tube, wherein two component metals of S31803 and GR2 can be made into the double-layer composite seamless steel tube, and the cold rolling method of the bimetal composite seamless steel tube comprises the following specific steps:

1. a cold rolling method for a bimetal composite seamless steel pipe comprises an S31803 duplex stainless steel seamless steel pipe and a GR2 pure titanium seamless steel pipe, and comprises the following specific steps:

1) firstly, selecting specifications of inner and outer layers of metal, and selecting a composite pipe phi 25 x 3 as a manufacturing standard;

Drawings

fig. 1 is a schematic structural diagram of a bimetal composite seamless steel tube manufactured by a cold rolling method of the bimetal composite seamless steel tube.

In the figure: 1-S31803 duplex stainless steel seamless steel pipe, 2-GR2 pure titanium seamless steel pipe.

during specific implementation, the specification of the middle pipe can be selected according to the outer diameter of a product and the requirements of the inner layer and the outer layer, and the basic rule is that the wall thickness deformation of the inner layer is slightly smaller than that of the outer layer.

2) firstly rolling an S31803 duplex stainless steel seamless steel pipe according to a cold rolling conventional process, wherein the specification is phi 27 x 2.5mm, the inner diameter is phi 22mm, and the length is 5.0 m;

3) then, the GR2 pure titanium seamless steel tube is rolled according to the cold rolling conventional process, the specification is phi 21.5 x 1.0mm, wherein, the tolerance range of the outer diameter is plus or minus 0.1mm, the inner diameter is phi 19.5mm, the tolerance range of the inner diameter is plus or minus 0.1mm, the wall thickness is 1.0mm, the tolerance range of the wall thickness is plus or minus 0.05mm, the length is 5.0m, and the tolerance range of the length is plus or minus 0.2 mm;

4) sleeving the S31803 duplex stainless steel seamless steel pipe and the GR2 pure titanium seamless steel pipe, wherein the S31803 duplex stainless steel seamless steel pipe is sleeved outside the GR2 pure titanium seamless steel pipe to form a bimetal composite pipe, and the sleeving gap of the bimetal composite pipe is controlled to be 0.40-0.60 mm;

5) Rolling the bimetal composite pipe by using a three-roller periodic cold pilger mill, wherein the clearance value after the nesting in the step 4) is controlled to be 0.4-0.6 mm, and the bimetal composite pipe is rolled into S31803 and GR2 bimetal composite pipes with the specification of phi 25 x 3 x 6000mm according to the incoming material specification phi 27 x 3.5 x 5000mm, and the process of the step is characterized in that:

5.1) the rolling speed of the cold pilger mill is 30-80 times/minute, the rolling speed of the joint parts of the front and the rear tube blanks is reduced to 30-40 times, and the rolling force is 25-35 tons;

5.2) the length of a core rod of the cold-rolling pipe mill is 520-540 mm, and the straightness error of the core rod, namely the bending degree is less than or equal to 0.2mm per meter, so that good straightness derivation of the cold-rolling composite pipe is ensured;

5.3) the rolling feed of the cold pilger mill is 2-4 mm/time, while the feed during rolling at the joint parts of the front and rear tube blanks is slowed down to 2-2.5 mm/time, thereby offsetting the rod-dropping difficulty caused by the increase of the length of the mandrel and ensuring the inner surface quality and the straightness requirement of the composite tube;

6) degreasing the inner surface and the outer surface of the rolled bimetal composite seamless steel pipe in the step 5), specifically, degreasing the inner surface and the outer surface of the rolled bimetal composite seamless steel pipe by adopting a secondary degreasing process according to a GR2 titanium alloy degreasing process, adopting a conventional degreasing medium at the temperature of 40-60 ℃, and performing treatment and soaking for 0.5-1 min, sealing two ends of the bimetal composite seamless steel pipe by using a plastic plug after the quality requirement of the inner surface of the composite pipe is met, degreasing the bimetal composite seamless steel pipe by adopting an S31803 super duplex stainless steel degreasing process, adopting a conventional degreasing medium at the temperature of 60-80 ℃, and performing treatment and soaking for 10-15 min to meet the quality requirement of the outer surface of the composite pipe;

7) Performing fixed cutting on the bimetal composite seamless steel pipe, specifically, performing end face fixed cutting processing on the bimetal composite seamless steel pipe subjected to deoiling treatment in the step 6) by adopting a metal band saw according to the length specified in the technical requirement;

8) the method comprises the following steps of (1) inspecting the bimetal composite seamless steel pipe, specifically, carrying out nondestructive inspection on the bimetal composite seamless steel pipe according to the specification of technical requirements;

9) and (3) after the steps 1) to 8) are finished, manufacturing the bimetal composite seamless steel pipe of S31803 and GR2, and obtaining a product meeting the technical quality requirement.

The cold rolling method for the bimetal composite seamless steel tube has the following beneficial effects that:

1. the process is reasonable, the rolling precision of the bimetal is high, the quality is easy to control, and the operation is convenient;

2. the investment of equipment and facilities is not increased, the cost is low, the production continuity is good, and the field implementation is easy;

3. The inner layer is treated to remove oil according to the requirements of a GR2 titanium alloy degreasing and pickling process, the outer layer of the S30813 duplex stainless steel is treated after the plug is blocked, the degreasing and deoiling quality is ensured, but the metal structure of the inner layer of GR2 is not corroded;

4. the nesting gap control technology avoids looseness caused by overlarge gaps and influence on the efficiency of smooth nesting due to overlarge gaps on the basis of meeting the nesting quality of the bimetal intermediate pipe, and is practical and efficient;

5. The cold rolling and the subsequent degreasing and pickling processes are tried and explored to form an effective operation process method, the other processes are still implemented by conventional processes, and the influence of process change on the production rhythm is reduced;

6. the rolling feed amount is strictly controlled, the bar stripping difficulty caused by the increase of the length of the core bar by more than 50mm is counteracted, and the requirements of the inner surface quality and the straightness of the composite pipe are ensured.

7. The rolled finished bimetal composite pipe meets the technical requirement that the inner layer and the outer layer have no clearance, the dimensional error value of the bimetal composite pipe is far lower than the technical requirement, the surface quality and the straightness are good, and the market demand is met.

8. The method has strong universality, and has certain reference and application values for the practice of the cold rolling method of the similar bimetal composite seamless steel pipe.