JPS60248870A - Strong, tough and wear resistant cast steel material - Google Patents

Abstract

PURPOSE:To provide the titled cast steel material which has high strength and high toughness, has the wear resistance improved as a result of increased resistance to softening by tempering and is reduced in cost by specifying the compsn. consisting of C, Si, Mn, Ni, Cr, Mo, V and Fe. CONSTITUTION:The strong, tough and wear resistant cast steel material consists of 0.25-0.32% C, 0.80-1.40% Si, 0.8-1.4% Mn, 0.20-0.80% Ni, 0.50-1.00% Cr, 0.20-0.70% Mo, 0.05-0.10% V and the balance Fe and can be used adequately for parts having resistance to wear by sand and soil such as a tooth of civil engineering machinery for which strength is required. C among the compsn. components of the above-mentioned cast steel material improves hardness, Si increases the resistance to softening by tempering, Mn improves hardenability, Ni is added for the purpose of improving the toughness, Cr and Mo improve the resistance to softening by tempering and hardenability and V is added to improve the strength and toughness by forming the finer crystal grains. The above-mentioned components are respectively added at the adequate amts. specified in the above-mentioned way. The use of a large amt. of particularly costly elements is thus avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to teeth, limp, cutting, and
This invention relates to tough and wear-resistant cast steel materials used for earth and sand wear-resistant parts such as cutting edges that require strength.

BACKGROUND OF THE INVENTION Many materials of this type have been developed in the past, including one disclosed in Japanese Patent Publication No. 26886/1986.

Problems to be Solved by the Invention Conventional wear-resistant steels still lack wear resistance, and they also have the problem of high cost due to their high Ni content and because they are forged products. .

Means for Solving the Problems The present invention has been made in view of the above-mentioned problems, and has high strength, high toughness, improved wear resistance, high resistance to temper softening, and low cost. It is a worn cast steel material.

That is, CO, 25-0.32%, Si o, go ~
1.40%, IdrLO, 80-1.40%, NiO
, 20~0.80%, C10, 50~1.00%, NO
Alloy steel is constructed by adding 0.20 to 0.70% and 0.05 to 0.10% of VO to the iron material, respectively, in weight ratios.

In the above-mentioned alloy according to the present invention, it is appropriate to add C in an amount of 0.25 to 0.32%, preferably about 0.3%, considering the balance between hardness and toughness. Si is an element that increases resistance to temper softening, but if added in a large amount it causes cracking, so it is appropriate to add it in an amount of 0.80 to 1.40%, preferably about 1.0%. Kn is 0.80 considering hardenability
It is appropriate to add about 1.40%, preferably about 1.0%. Ni is 0.20 to 0.80% for the purpose of improving toughness,
Preferably, it is appropriate to add about 0.4%. Cγ is 0.50 to 1.00 to improve tempering softening resistance and hardenability.
%, preferably about 0.6%. No
For the same reason as the addition of Cγ, it is appropriate to add 0.20 to 0.70%, preferably about 0.4%. V has a great effect when used as a grain refining element, and the appropriate amount of V added is 0.05 to 0.10%, preferably about 0.07%.

EXAMPLES The table below shows examples of cast steel materials according to the present invention, and the mechanical properties of the cast steel materials in these examples are shown in FIG.

The characteristics of the cast steel material of the present invention in the above embodiments are as follows.

(+) In the product water-quenched at 900°C and tempered at 300°C, high tensile strength of 1-75, high strength of 9/j, and high hardness of HxC5Q were obtained.

(2) Compared to other steels, it has higher resistance to temper softening and less decrease in hardness even at high temperatures during wear, so it can be used under harsh conditions such as high temperatures of 200 to 300 degrees Celsius. Excellent wear resistance.

(3) Excellent castability and no cracking.

(4) Since the steel of the present invention shows a decrease in impact value due to carbide reaction at around 400°C, a suitable tempering temperature is 300°C.

(5) Results of cowing wear test The steel of the present invention was compared to the conventional material (
SESC-2M) exhibits approximately 1.1 times the wear resistance (Figure 2).

(6) The teeth made of the steel of the present invention are made of conventional material (5H5C-2H
'), the cost index is 0.8 (Figure 3).

Effects of the Invention According to the present invention, the material has excellent strength and hardness, and the addition of a small amount of V refines the crystal grains, improving strength and toughness.Furthermore, it has a high resistance to tempering softening, so it can be easily used during use. It has good wear resistance even at high temperatures. Furthermore, compared to conventional products, the wear resistance is 1.1 times higher and the cost is 0.
．． 8 and has economically excellent properties.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the mechanical properties of the steel of the present invention, FIG. 2 is a diagram showing a comparison of wear resistance, and FIG. 3 is a diagram showing a comparison of costs. Applicant Komatsu Ltd. Representative Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto Figure 1

Claims (1)

[Claims] CO, 25~0.32%, sio, so~1.40
%, KnO 08-1.4%, NiO, 20-0.80
%, C10,50~1.00%, MO0,20~0.7
0%, Vo, 05-0. Tough and wear-resistant cast steel material consisting of IO%Ft balance.