High-strength vermicular cast iron and preparation method thereof

A technology of ductile vermicular cast iron, applied in the field of new high-strength ductile vermicular graphite cast iron and its preparation, can solve the problems that have not been found in literature reports, etc., and achieve the effects of easy control of vermicular treatment, good comprehensive performance of products, and simple operation of preparation process

Active Publication Date: 2012-04-11
XIAN KANGBO NEW MATERIAL TECH
View PDF6 Cites 20 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Although a lot of work has been done on vermicular graphite cast iron at home and abroad, and many achievements have been made, many difficulties have been encountered in the process of popularizing and applying this material in industry. The main performance is that the creep treatment of the material is unstable during preparation, the creep rate is low and difficult to control, and the comprehensive performance is poor (very low plasticity, δ<1%)
[0006] After searching in the existing information system and network, no literature reports similar to the alloy material and preparation method of the present invention have been found

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
  • High-strength vermicular cast iron and preparation method thereof
  • High-strength vermicular cast iron and preparation method thereof
  • High-strength vermicular cast iron and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A high strength and toughness compacted graphite cast iron, its chemical composition is (weight percent): C: 3.6%, Si: 2.4%, Cu: 0.3%, Mo: 0.3%, Mn: 0.5%, Sn: 0.03%, Sb: 0.02 %, the rest is composed of iron and unavoidable impurities. In the vermicularization process, a commercially available rare earth-magnesium-silicon vermicular agent was used as the vermicular agent, the addition amount was 0.8%, the vermicularization temperature was 1475°C, and the vermicularization rate was 85%. Prepared into high strength and toughness compacted graphite iron castings. In the heat treatment process, the casting is kept at 930°C for 2 hours, placed in a salt solution at 350°C for 2 hours, and then air-cooled. The compacted graphite iron casting has excellent comprehensive performance and process formability. The matrix in its metallographic structure is composed of lower bainite and austenite, and the shape of graphite phase is worm-like, see figure 1 and figure 2 . The ...

Embodiment 2

[0028] A high strength and toughness compacted graphite cast iron, its chemical composition is (weight percent): C: 3.8%, Si: 2.1%, Cu: 0.2%, Mo: 0.2%, Mn: 0.2%, Sn: 0.02%, Sb: 0.01 %, the rest is composed of iron and unavoidable impurities. The vermicular agent is a commercially available rare earth-magnesium-silicon vermicular agent, the addition amount is 0.5%, the vermicular temperature is 1450°C, and the vermicular rate is 90%. Prepared into high strength and toughness compacted graphite iron castings. The casting is kept at 900°C for 1.5 hours, put into 330°C salt solution for 1.5h, and then air-cooled to make austenitic and bainite vermicular graphite iron castings. The compacted graphite cast iron casting has excellent comprehensive performance and process formability. The tensile properties at different temperatures are shown in Table 1. The metallographic structure of the compacted graphite cast iron is shown in Table 1. image 3 .

[0029] Table 2

[0030] ...

Embodiment 3

[0032] A high-strength compacted graphite cast iron, its chemical composition is (weight percent): C: 3.6%, Si: 2.6%, Cu: 0.4%, Mo: 0.2%, Mn: 0.6%, Sn: 0.04%, Sb: 0.008 %, the rest is composed of iron and unavoidable impurities. The vermicular agent is a commercially available rare earth-magnesium-silicon vermicular agent, the addition amount is 0.6%, the vermicular temperature is 1500°C, and the vermicular rate is 90%. Prepared into high strength and toughness compacted graphite iron castings. The casting is kept at 950°C for 1.5 hours, put into 360°C salt solution for 3h, and then air-cooled to make austenitic and bainite vermicular graphite iron castings. The tensile properties at different temperatures are shown in Table 3,

[0033] table 3

[0034] temperature(℃) Tensile strength (Mpa) Elongation (%) room temperature 840 3.0 350 827 4.0 550 463 5.0

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

PropertyMeasurementUnit
tensile strengthaaaaaaaaaa
elongationaaaaaaaaaa
Login to view more

Abstract

The invention provides high-strength vermicular cast iron and a preparation method thereof. The high-strength vermicular cast iron consists of the following components in percentage by weight: 3.4-3.8 percent of C, 2.1-2.6 percent of Si, 0.2-0.6 percent of Cu, 0.2-0.5 percent of Mo, 0.2-0.8 percent of Mn, 0.02-0.04 percent of Sn, 0.004-0.032 percent of Sb and the balance of iron and inevitable impurities. The microscopic structure of the vermicular cast iron provided by the invention consists of a substrate and vermicular graphite, and the vermicular rate surpasses 85 percent. The vermicular cast iron can be prepared into vermicular cast iron with excellent comprehensive performance by preserving heat at the temperature 900-950 DEG C for 1.5-3 hours, preserving heat in a saline solution at the temperature 320-360 DEG C for 1.5-3 hours and performing air cooling. The vermicular cast iron provided by the invention has the characteristics of high strength, high plasticity, heat resistance, impact resistance, fatigue resistance, high casting forming performance, and the like. The tensile strength of the high-strength vermicular cast iron at the room temperature is 780-950 MPa, and theelongation percentage is more than or equal to 3 percent, so that the requirements of a high-power diesel engine on the materials of key parts are met. The preparation method of the high-strength vermicular cast iron provided by the invention has a stable vermiculation process, a high vermicular rate and a simple process, and is convenient to operate.

Description

technical field [0001] The invention belongs to the field of metal materials, and relates to a novel high-strength and tough vermicular graphite cast iron and a preparation method thereof. Background technique [0002] Modern diesel engines have the characteristics of high power per liter, compact structure, complex casting shapes, large heat loads, and high degrees of reinforcement. New updates have been made not only to the design technology, but also to the materials and manufacturing technologies of critical parts such as the diesel engine body and cylinder head. High requirements require that materials not only have high room temperature and high temperature mechanical properties, excellent thermal conductivity and shock absorption properties, and excellent thermal fatigue properties, but also require high compactness, uniformity, and reliability. Compacted graphite cast iron has very good mechanical properties at room temperature and high temperature, excellent therma...

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): C22C37/10C22C33/08
Inventor 李建平郭永春杨忠杨通王萍
Owner XIAN KANGBO NEW MATERIAL TECH
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