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

Pipe nodular cast iron manufacturing method

A technology of nodular cast iron and a manufacturing method, applied in the field of casting, can solve the problem that the high temperature mechanical properties and oxidation resistance requirements of exhaust manifold materials cannot be met, the high temperature creep resistance and creep rupture resistance are poor, and the exhaust manifold materials Anti-oxidation performance and other problems, to achieve the effect of improving high temperature creep resistance and creep rupture resistance, improving spheroidization, and improving high temperature mechanical properties

Inactive Publication Date: 2015-07-15
天津中联金属制品有限公司
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In recent years, out of the consideration of protecting the environment and saving resources, increasing the compression ratio, improving fuel combustion efficiency and reducing emissions, new requirements have been continuously put forward for automobile engines. In order to adapt to the application of catalytic technology and turbocharging technology And the exhaust temperature of the engine continues to rise, and the requirements for the high-temperature mechanical properties and oxidation resistance of the exhaust manifold of the automobile engine are getting higher and higher. Therefore, the high-temperature resistance requirements of the exhaust manifold of the automobile engine have reached 900 ℃ However, the existing domestic exhaust manifold materials generally can only meet the requirements for use at a temperature of about 750°C; with the further improvement of engine performance, especially the continuous improvement of turbocharging technology, the exhaust manifold The working temperature will also increase. In addition, the exhaust manifold has been working in a high temperature cycle for a long time, the heating temperature is uneven, the difference between the surface layer and the inner cavity is hundreds of degrees, and the working conditions are harsh. The oxidation resistance of the exhaust manifold material at high temperature The performance directly affects the service life of the exhaust manifold. The tensile strength of ordinary ductile iron materials is only about 50N / mm2 at a temperature of 650°C. The number of times is about 100 times, and the high-temperature creep resistance and creep fracture resistance are poor, which can no longer meet the high-temperature mechanical properties and oxidation resistance requirements of exhaust manifold materials.

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
  • Pipe nodular cast iron manufacturing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Prepared according to the above steps 1) and 2), wherein the components in the steel scrap and the mass fractions of each component in step 1) are: C: 0.17%, S: 0.012%, P: 0.020%, Mn: 0.24%, Si: 0.30%.

[0018] The mass fraction of Mg in the magnesium alloy in step 1) is 45%.

[0019] The mass fraction of Re in the rhenium alloy in step 1) is 35%.

[0020] The nodulizer in step 2) is a rare earth magnesium alloy FeS iMg8Re7 nodulizer.

[0021] The ferrosilicon inoculant in step 2) is FeSi75 alloy, wherein the mass fraction of Si is 60%.

[0022] The mass fraction of Si in the barium silicon inoculant in step 2) is 35%.

Embodiment 2

[0024] Prepared according to the above steps 1) and 2), wherein the components in the steel scrap and the mass fractions of each component in step 1) are: C: 0.19%, S: 0.014%, P: 0.023%, Mn: 0.25%, Si: 0.35%.

[0025] The mass fraction of Mg in the magnesium alloy in step 1) is 48%.

[0026] The mass fraction of Re in the rhenium alloy in step 1) is 38%.

[0027] The nodulizer in step 2) is a rare earth magnesium alloy FeSiMg8Re7 nodulizer.

[0028] The ferrosilicon inoculant in step 2) is FeSi75 alloy, wherein the mass fraction of Si is 66%.

[0029] The mass fraction of Si in the barium silicon inoculant in step 2) is 40%.

Embodiment 3

[0031] Prepared according to the above steps 1) and 2), wherein in step 1) the components in steel scrap and the mass fractions of each component are: C: 0.21%, S: 0.016%, P: 0.025%, Mn: 0.28%, Si: 0.40%.

[0032] The mass fraction of Mg in the magnesium alloy in step 1) is 50%.

[0033] The mass fraction of Re in the rhenium alloy in step 1) is 45%.

[0034] The nodulizer in step 2) is a rare earth magnesium alloy FeSiMg8Re7 nodulizer.

[0035] The ferrosilicon inoculant in step 2) is FeSi75 alloy, wherein the mass fraction of Si is 70%.

[0036] The mass fraction of Si in the barium silicon inoculant in step 2) is 45%.

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
hardnessaaaaaaaaaa
yield ratioaaaaaaaaaa
elongationaaaaaaaaaa
Login to View More

Abstract

The invention belongs to the technical field of casting and relates to a pipe nodular cast iron manufacturing method. The method comprises iron liquid melting preparation, nodulizing and inoculation treatment. The pipe nodular cast iron greatly improves high temperature creep resistance and creep fracture resistance of a casting, has cyclic failure frequency of 410-440 times at a thermal cyclic temperature of 500-600 DEG C, has high temperature tensile strength of 130-140N / mm<2> at a temperature of 600 DEG C, and has tensile strength of 620-650N / mm<2>, yield strength of 500-530N / mm<2>, elongation percentage of 4.5-5.5%, hardness of 245-255HB and a yield ratio of 0.8-0.9 at a room temperature. The pipe nodular cast iron has a high yield ratio and good heat resistance, reduces casting deformation probability, prolongs a service life and satisfies requirements on high temperature mechanical properties and antioxidation performances of nodular cast iron.

Description

technical field [0001] The invention belongs to the technical field of casting, and in particular relates to a method for manufacturing ductile iron for pipe fittings. Background technique [0002] In recent years, out of the consideration of protecting the environment and saving resources, increasing the compression ratio, improving fuel combustion efficiency and reducing emissions, new requirements have been continuously put forward for automobile engines. In order to adapt to the application of catalytic technology and turbocharging technology And the exhaust temperature of the engine continues to rise, and the requirements for the high-temperature mechanical properties and oxidation resistance of the exhaust manifold of the automobile engine are getting higher and higher. Therefore, the high-temperature resistance requirements of the exhaust manifold of the automobile engine have reached 900 ℃ However, the existing domestic exhaust manifold materials generally can only m...

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): C22C37/10C22C37/04C22C33/08C21C1/10B22D1/00
CPCY02P10/20
Inventor 刘伟王兰翠刘夏利
Owner 天津中联金属制品有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products