CN100420762C

CN100420762C - TiC-WC based alloy products

Info

Publication number: CN100420762C
Application number: CNB2006100209239A
Authority: CN
Inventors: 于绍武; 黄宇; 王晓灵
Original assignee: Zigong Cemented Carbide Co Ltd
Current assignee: Zigong Cemented Carbide Co Ltd
Priority date: 2006-04-28
Filing date: 2006-04-28
Publication date: 2008-09-24
Anticipated expiration: 2026-04-28
Also published as: CN1865477A

Abstract

The present invention relates to TiC-WC base alloy guiding rollers, valve cores and valve seats belonging to the field of cermet and hard alloy production. The present invention comprises the following components: 30 to 60 wt% of TiC, 15 to 55 wt% of WC and 0 to 3.0 wt% of Ta as a hard phase, 10 to 30 wt% of Co+Ni as a binding phase and 0 to 3.0 wt% of Cr as an inhibiting agent of crystal grain growth. The density of the products is only 0.3 to 0.5 time of that of a WC-base hard alloy, bending strength can reach 2500 N/mm<2>, and hardness (HAR) is from 87.0 to 90.5. The products are uniform in metal structure, full in grains and no taper angle. Thus, the present invention has the characteristics of light weight, low porosity, high strength and hardness, strong high-temperature wear resistance, corrosion resistance and oxidation resistance, good thermal stability, long service life (which is prolonged by 35 to 40% than that of the prior art), etc. The disadvantages of low hardness and high-temperature strength, poor abrasion resistance, difficult sintering control, poor forming accuracy, poor stability, short service life, etc. of the prior art are overcome.

Description

The TiC-WC based alloy products

Technical field

The invention belongs to TiC-WC based alloy products in sintering metal, the CEMENTED CARBIDE PRODUCTION field, particularly a kind of with TiC and WC be main hard mutually, be alloy products such as the guide roll class of bonding phase and spool valve seat with Ni/Co.

Background technology

Be used on the high-speed rod steel rolling line that the red steel behind line, the rolling bar is transported to the roller groove with guide rolls such as the deflector roll that prevents to take place around accidents such as steel and whippings, conduit, pinch rolls, owing to be in the down work of mal-condition of 900～1100 ℃ of high temperature and 35000 rev/mins of left and right sides rotating speeds for a long time, therefore the density (proportion) of hot strength, high temperature abrasion resistance, oxidation-resistance and the parts of parts itself is had relatively high expectations.Traditional guide roll generally adopts cast steel and rapid steel to make, though it is wide to have material source, advantages such as production cost is lower, but exist high temperature resistant and wear no resistance, the short and easy magnetization of cracky, work-ing life, in use the iron filings that produce because of wearing and tearing very easily stick to surface such as deflector roll and scratch section bar, influence disadvantage such as quality product.At these disadvantage publication numbers is CN1079996A, denomination of invention is a kind of with the titanium carbide, the wolfram varbide that account for gross weight 45～59.5wt% or add small amount of tantalum carbide as the hard phase for the patent documentation of " light hard alloy that hot-work is used " discloses, with cobalt, nickel and the molybdenum that accounts for gross weight 40.5～55wt% serve as bonding mutually, the roll class hot-work light hard alloy goods that form by the powder metallurgical technique sintering.This alloy one, bonding phase composition are up to more than the 40wt%, though the high bending strength that can improve alloy of bonding phase content is too much, yielding because of amount of liquid phase when also having reduced wear resistance and hardness and sintering simultaneously; Two, in alloy ingredient, add Mo (molybdenum) element, reduce the intensity of alloy, particularly hot strength mutually and around being coated on the TiC particle though the wetting TiC of Mo energy makes sintering densification can form fragility simultaneously again; Three, there are TiC, TiC-WC, TiC-Mo in the alloy organizing simultaneously ₂C, WC and sosoloid bonding equate 5 mutually, phase composition complexity is wayward.Thereby the above-mentioned background technology exist hardness and hot strength low, wear no resistance defective such as the control of goods sintering is difficult, formed precision and poor stability, and work-ing life is still short.

Summary of the invention

The objective of the invention is defective at the background technology existence, research and develop a kind of TiC-WC based alloy products, improve guide roll class and spool, comprehensive mechanical performance, high temperature strength and the wear resistance at elevated temperature of valve seat based article, the rotten performance of chemically-resistant to reach, effectively prolong goods work-ing life, reduce purpose such as use cost.

Solution of the present invention be reduce bonding in alloy ingredient ratio and only adopt Co and Ni as boning mutually, adjust alloy ingredient and TiC, the WC ratio in alloy ingredient simultaneously, thereby realize its purpose.Therefore the composition of TiC-WC based alloy products of the present invention comprises hard and reaches the bonding phase mutually; Key is also to contain in its composition the grain growth inhibitor Cr of 0～3.0wt%, and hard contains TiC:30～60wt%, WC:15～55wt%, Ta:0～3.0wt% in mutually, and bonding phase Co+Ni is 10～30wt%.

Bonding phase Co+Ni is in the described alloy product: 10～30wt%, in the total mutually composition weight of bonding, wherein: Co is that 6.5～50wt%, Ni are 50～93.5wt%.

Extrudate density of the present invention is low, only be 0.3～0.5 times of WC base cemented carbide density, bending strength can be up to 2500N/mm ², porosity is A ₀₂B ₀₀C ₀₀, hardness HRA87.0～90.5, metallographic structure is even, and crystal grain is full, no wedge angle.Thereby have that light weight, porosity are low, intensity and hardness height, high-temperature wearable, erosion resistance and oxidation-resistance be strong, Heat stability is good, can prolong characteristics such as 35～40% work-ing life than background technology.

Description of drawings

Fig. 1. be embodiment 1 goods * 1500 times of metallographic structure photos; The black globe is that hard phase, light-colored part are the bonding phase among the figure.

Embodiment

Embodiment 1: present embodiment is example (by every batch of 100kg batching) to produce high-speed rod steel rolling guide roll:

A, wet-milling batching: will meet the industrial production standard and place in the ball mill with 56.5kgTiC, 18kgWC, 14kgNi, 10kgCo and 1.5kgCr powder, temperature mill mixes after 64 hours, add paraffin 2.0kg continue ball milling and mix after, slip is crossed 320 mesh sieves, the gained mixed powder is sent in the vacuum drier under 100 ℃ of temperature drying treatment removing wet grinding media, cooling after homogenizing is handled, mixed powder is stand-by; The present embodiment wet grinding media is a hexane;

B, compression molding and presintering: the gained mixed powder is sent in the mould, be pressed into guide roll base just; Send into the inherent 500 ℃ of temperature lower calcinations of vacuum oven 75 minutes then, except that the shape that is machined to the goods requirement behind deparaffnize, the furnace cooling;

C, sintering: will send into low pressure through the work in-process that step B is processed into and burn in the stove, under 1450 ℃ of temperature the pressurize sintering 25 minutes, and promptly get the purpose goods behind the furnace cooling.

Accompanying drawing 1, be present embodiment * 1500 times metallographic structure photos; Resulting product is after testing: density 6.5g/cm ³, hardness HRA＞87.0, bending strength 2200N/mm ², porosity A ₀₂B ₀₀C ₀₀On-the-spot rolling test sheet groove 4000T in work-ing life.

Embodiment 2:, corrosion resistant ball valve spool wear-resisting to produce and valve seat are example (by every batch of 100kg batching):

A, wet-milling batching: industrial 30kgTiC, 54kgWC, 7.5kgNi, 7.5kgCo and 1.0kgTa powder are placed in the ball mill; Following technology and parameter (comprising B, C step) are all identical with embodiment 1.

The present embodiment goods are after testing: density 9.0g/cm ³, hardness HRA 〉=90.5, bending strength 2000N/mm ², porosity A ₀₂B ₀₀C ₀₀

Claims

1. TiC-WC based alloy products, the goods composition is by the grain growth inhibitor Cr of 0～3.0wt%, hard phase TiC:30～60wt%, WC:15～55wt%, Ta:0～3.0wt%, bonding phase Co+Ni:10～30wt% forms, and the porosity of goods is A ₀₂B ₀₀C ₀₀

2. by the described TiC-WC based alloy products of claim 1, it is characterized in that in total mutually composition weight: the Co of bonding be that 6.5～50wt%, Ni are 50～93.5wt%.