CN103667858A - Production method of ultralow-temperature spheroidal graphite cast iron - Google Patents

Abstract

The invention relates to a production method of an ultralow-temperature spheroidal graphite cast iron. The production method comprises the steps: (1) selecting materials: cast iron, high-quality carbon steel, a spheroidizing agent and a Si-Ba inoculant; (2) optimizing ingredients: 50-60 parts of cast iron, 10-20 parts of scrap steel and 20 parts of foundry returns; (3) controlling components: 3.6-3.9 parts of C, 1.8-2.3 parts of Si, less than 0.2 part of Mn, less than 0.04 part of P, less than 0.02 part of S, 0.04-0.06 part of Mg and less than 0.02 part of Re; (4) smelting by using a medium frequency furnace, wherein the tapping temperature is 1500-1550 DEG C, the addition amount of the spheroidizing agent is 1.4-1.6, the inoculation amount is 0.5-0.8, and the pouring temperature is 1380-1420 DEG C; (5) carrying out thermal treatment: carrying out high temperature annealing by using an electric box furnace, homogenizing a tissue, eliminating stress, and carrying out thermal treatment on an attached test bar along with the furnace to obtain a finished product of the ultralow-temperature spheroidal graphite cast iron. The production method is simple and relatively low in cost, and the obtained spheroidal graphite cast iron is high in strength, good in toughness and strong in wear resistance.

Description

Very low temperature spheroidal graphite Cast Iron Production method

Technical field

The invention belongs to spheroidal graphite cast iron field, especially a kind of very low temperature spheroidal graphite Cast Iron Production method.

Background technology

Spheroidal graphite cast iron is to obtain globular graphite by nodularization and inoculation, has effectively improved the mechanical property of cast iron, has particularly improved plasticity and toughness, thereby obtains than carbon steel high intensity also.Spheroidal graphite cast iron is 20th century a kind of meehanite cast iron materials of growing up of the fifties, and its over-all properties, close to steel, just based on its excellent performance, has been successfully used to cast some stressed complexity, the part that intensity, toughness, wear resistance are had relatively high expectations.Spheroidal graphite cast iron developed rapidly for be only second to graphitic cast iron, application cast iron materials very widely.So-called " with iron for steel ", mainly refers to spheroidal graphite cast iron.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of very low temperature spheroidal graphite Cast Iron Production method is provided, this production method is simple, and cost is lower, and the spheroidal graphite cast iron intensity that obtains is high, good toughness, wear resistance are strong.

The present invention solves its technical problem and is achieved through the following technical solutions:

A very low temperature spheroidal graphite Cast Iron Production method, its method steps is as follows:

(1), select materials: adopt the low TiQ10 trade mark of the low S of the low P pig iron; Adopt highquality carbon steel; Adopt common 7-1 nodulizing agent and silicon titanate innoculant;

(2), feed proportioning optimization: pig iron 50-60 part, steel scrap 10-20 part, 20 parts of foundry returns;

(3), Composition Control: C 3.6-3.9 part, Si 1.8-2.3 part, Mn<0.2 part, P<0.04 part, S<0.02 part, Mg 0.04-0.06 part, Re<0.02 part;

(4), Melting control: adopt electrosmelting of intermediate frequency.Tapping temperature 1500-1550 ℃, nodulizing agent add-on 1.4-1.6 part, pregnant amount 0.5-0.8 part, teeming temperature 1380-1420 ℃;

(5), thermal treatment: adopt cabinet-type electric furnace to carry out high temperature annealing, uniform formation, eliminates stress, and attached test coupon is managed with furnace treatment, obtains very low temperature spheroidal graphite cast iron finished product.

Advantage of the present invention and beneficial effect are:

Preparation method of the present invention is simple, and cost is lower, and the spheroidal graphite cast iron intensity that obtains is high, good toughness, wear resistance are strong.

Embodiment

Below by specific embodiment, the invention will be further described, and following examples are descriptive, is not determinate, can not limit protection scope of the present invention with this.

A very low temperature spheroidal graphite Cast Iron Production method, its method steps is as follows:

(1), select materials: adopt the low TiQ10 trade mark of the low S of the low P pig iron; Adopt highquality carbon steel; Adopt common 7-1 nodulizing agent and silicon titanate innoculant;

(2), feed proportioning optimization: pig iron 50-60 part, steel scrap 10-20 part, 20 parts of foundry returns;

(3), Composition Control: C 3.6-3.9 part, Si 1.8-2.3 part, Mn<0.2 part, P<0.04 part, S<0.02 part, Mg 0.04-0.06 part, Re<0.02 part;

(4), Melting control: adopt electrosmelting of intermediate frequency.Tapping temperature 1500-1550 ℃, nodulizing agent add-on 1.4-1.6 part, pregnant amount 0.5-0.8 part, teeming temperature 1380-1420 ℃;

(5), thermal treatment: adopt cabinet-type electric furnace to carry out high temperature annealing, uniform formation, eliminates stress, and attached test coupon is managed with furnace treatment, obtains very low temperature spheroidal graphite cast iron finished product.

Claims (1)

1. a very low temperature spheroidal graphite Cast Iron Production method, is characterized in that: the method step is as follows:

(1), select materials: adopt the low TiQ10 trade mark of the low S of the low P pig iron; Adopt highquality carbon steel; Adopt common 7-1 nodulizing agent and silicon titanate innoculant;

(2), feed proportioning optimization: pig iron 50-60 part, steel scrap 10-20 part, 20 parts of foundry returns;

(3), Composition Control: C 3.6-3.9 part, Si 1.8-2.3 part, Mn<0.2 part, P<0.04 part, S<0.02 part, Mg 0.04-0.06 part, Re<0.02 part;

(4), Melting control: adopt electrosmelting of intermediate frequency.Tapping temperature 1500-1550 ℃, nodulizing agent add-on 1.4-1.6 part, pregnant amount 0.5-0.8 part, teeming temperature 1380-1420 ℃;

(5), thermal treatment: adopt cabinet-type electric furnace to carry out high temperature annealing, uniform formation, eliminates stress, and attached test coupon is managed with furnace treatment, obtains very low temperature spheroidal graphite cast iron finished product.