Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Molding heat treatment method for standard duplex steel elbow

A heat treatment method and dual-phase steel technology, applied in the field of grade material forming, can solve the problems of elbow cracks, unresolved, control, etc., and achieve the effect of improving the qualification rate and reducing the possibility of cracks

Active Publication Date: 2020-02-25
SINOPEC ENG +1
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] None of the above technical solutions mentioned, let alone solve the technical problem of cracks in the elbow due to the fact that the steel pipe cools down quickly after it comes out of the heating furnace, and it is difficult to control the required temperature during the bending process.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] It includes the following steps: the tube blank of standard duplex steel elbow must be preheated to the special mold before bending, and the preheating can be done by resistance heating, preheating to 300 ℃; To 1080°C, the calculation value of holding time: 1 minute / mm; when the temperature is as low as 840°C during each bending forming process, the bending must be stopped immediately, and accelerated cooling and forced air cooling are used to quickly cool it to below 300°C ;The formed elbow is obtained after multiple bendings. The heat treatment condition after the last bending is: 1040°C, the calculation value of the holding time: 1 minute / mm, and the accelerated cooling is adopted, and the forced air cooling is used to quickly cool it to below 300°C .

[0029] The standard dual-phase steel elbow products produced by the above treatment method are in good use, and the first pass rate of the elbow products is 100%.

Embodiment 2

[0031] It includes the following steps: the tube blank of standard duplex steel elbow must be preheated to the special mold before bending, and the preheating can be done by resistance heating, preheating to 300 ℃; To 1090°C, the calculation value of holding time: 1.5 minutes / mm; when the temperature is as low as 850°C during each bending forming process, the bending must be stopped immediately, and accelerated cooling and forced air cooling are used to quickly cool down to below 300°C ;The elbow is obtained after several times of bending, the heat treatment condition after the last bending is: 1050°C, the calculation value of the holding time: 2 minutes / mm, take accelerated cooling, place it in a cold water pool to make it cool quickly to Below 300°C.

[0032] The standard dual-phase steel elbow products produced by the above treatment method are in good use, and the first pass rate of the elbow products is 100%.

Embodiment 3

[0034] It includes the following steps: the tube blank of standard duplex steel elbow must be preheated to the special mold before bending, and the preheating can be done by resistance heating, preheating to 300 ℃; to 1100°C, the calculation value of the holding time: 1 minute / mm; when the temperature is as low as 860°C during each bending forming process, the bending must be stopped immediately, accelerated cooling is adopted, and it is placed in a cold water pool to cool quickly to 300°C Below ℃; the formed elbow is obtained by bending for many times, the heat treatment condition after the last bending is: 1060℃, the calculation value of holding time: 2 minutes / mm, adopt accelerated cooling, forced air cooling to quickly cool to 300 below ℃.

[0035] The standard dual-phase steel elbow products produced by the above treatment method are in good use, and the first pass rate of the elbow products is 100%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to the field of high-grade material molding, in particular to a molding heat treatment method for a standard duplex steel elbow. The method comprises steps as follows: 1), performing bending for molding on a special elbow molding die after heating of a pipe blank, and stopping bending immediately and performing accelerated cooling when the temperature of the pipe blank is aslow as 840-860 DEG C; 2), repeating the step 1) until the elbow is molded; and 3), performing heat treatment on the molded elbow, and then performing accelerated cooling to obtain the standard duplexsteel elbow. According to the molding heat treatment method for the standard duplex steel elbow, a bending temperature range of the pipe blank is strictly limited, so that the probability of cracks inthe pipe blank in a molding process is greatly reduced, and the qualification rate of elbow molding is increased.

Description

technical field [0001] The invention relates to the field of high-grade material forming, in particular to a heat treatment method for standard dual-phase steel elbow forming. Background technique [0002] With the excellent chloride stress corrosion resistance of duplex steel, it is more and more widely used in the field of petrochemical industry. Elbows are used in petrochemical equipment and pipelines. The elbows need to be heated to a certain temperature during the bending process. Then use a special mold to form. Due to the high strength of the dual-phase steel, multiple moldings are required. The dual-phase steel is particularly sensitive to temperature. According to the general theory, the ferrite will transform into a σ-brittle phase when it is lower than 1000 °C. However, due to the difficulty of forming, the traditional bending and heat treatment process requires that the bending must be completed before the temperature drops to 950°C, which is actually difficult t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C21D1/00C21D6/00C21D8/00C21D9/00C22C38/40B21D7/00B21D7/16
CPCB21D7/00B21D7/162B21D7/165C21D1/00C21D6/004C21D8/005C21D9/0062C21D9/0068C22C38/40
Inventor 王金光董汪平尹青锋宫博李黎
Owner SINOPEC ENG
Features
  • Generate Ideas
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com