Method for overcoming explosion defect of 4140 steel tubing hanger body

An oil pipe hanging and body technology, applied in the field of workpiece forging, can solve problems such as pattern defects of folding knives, and achieve the effects of avoiding harmful tissue, reducing folding, and reducing knife patterns

Active Publication Date: 2020-09-29
NANJING DEV ADVANCED MFG
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Based on the above, in view of the macroscopic characteristics of the cracks on the main body of the pendant, the macro-microscopic morphology of the open crack fracture and the inspection results of the metallographic samples taken, there is a folding knife pattern defect at the transition arc of the steps of the main body of the pendant.

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for overcoming explosion defect of 4140 steel tubing hanger body
  • Method for overcoming explosion defect of 4140 steel tubing hanger body

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0025] The present invention is described in further detail now in conjunction with accompanying drawing.

[0026] Such as figure 1 Shown, a kind of method of the present invention overcomes the defect of 4140 steel tubing hanger body bursting, comprises

[0027] Step 1: Select 350 square meters of 4140 blanks and put them into the heating furnace; set the temperature at 500±10°C, open the furnace door ajar, set the heating rate at 100°C / hour, and wait until the temperature in the furnace reaches 500±10°C , close the furnace door, and keep warm for two hours.

[0028] The temperature is set at 800±10°C, the heating rate is set at 50°C / hour, and when the temperature in the furnace reaches 800±10°C, keep warm for two hours.

[0029] The temperature is set at 1250±10°C, and the heating rate is set at 25°C / hour. When the temperature in the furnace reaches 1250±10°C, keep warm for two hours before leaving the oven.

[0030] Step 2: Rough machining of the blank, including elongat...

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 a method for overcoming the explosion defect of a 4140 steel tubing hanger body. Firstly, a blank is heated section by section, then basic procedures are prepared, then die forging is carried out, then lime sand cooling is used for cooling, and finally a formed workpiece is subjected to quenched-tempered heat treatment. As the blank is slowly heated, the internal structureof the blank slowly changes, the effects of refining grain and homogenizing the structure are achieved, the actual grain size can reach a 7-10 level, and harmful structures such as a Widmannstatten structure generated by overburning and overheating are avoided. Due to the manner of die forging, too large surface stress triggered by hammer forging of free forging is avoided, sequential forging iscarried out in multiple directions, the fluidity of the blank is improved, and knife patterns and main cracks are avoided. During final quenching, the quenching cooling speed is reduced, the cooling speed of a martensite transformation region is reduced, thus, transgranular extension is avoided, structural stress of martensite transformation is reduced, and macroscopic cracks are avoided.

Description

technical field [0001] The invention relates to a method for overcoming the cracking defect of a 4140 steel oil pipe hanger body, and belongs to the technical field of workpiece forging. Background technique [0002] The 350 m3 4140 billet was forged with a 3t forging hammer to form the body of the oil pipe hanger. The forged billet of the hanger body was subjected to final quenching and tempering heat treatment after rough machining. In order to find out the cause of the defect, one of them was dissected and sampled for inspection. [0003] After investigation and research, it was found that the cracks on the main body of the pendant were ring cracks and longitudinal cracks coexisting, and the cracks were rigid and straight. The annular cracks are located at the transition arc of the steps and distributed along the circumference. The longitudinal cracks are connected with the annular cracks at the first large step and distributed along the radial direction. Regardless of...

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
Patent Type & Authority Applications(China)
IPC IPC(8): B23P15/00
CPCB23P15/00
Inventor 陈昌华陈海山汪海潮张利张洪孔德贵刘晓磊哈曜陈新华施虹屹龚洋道陈洁
Owner NANJING DEV ADVANCED MFG
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap