CN1027872C - High-hardness wear-proof welding electrode without preheating - Google Patents

Abstract

The present invention relates to a wear-proof welding electrode with high hardness. Without preheating, the welding electrode has high hardness (HRC67-70) and favorable crack resistance simultaneously. The deposited metal of the welding electrode has the following chemical components in weight percentages: 1% to 2% of carbon, 1% to 2% of silicon, 4% to 8% of vanadium, 0.2% to 1.5% of boron, 0.5% to 1% of manganese, 2% to 5% of chromium, 0.2% to 0.5% of titanium, 7% to 10% of molybdenum, 0.5% to 1.5% of niobium, at most 0.029% of phosphorus, at most 0.043% of sulfur and balance of ferrum as the rest. The welding electrode can be used for the wear-proof build-up welding of work pieces.

Description

High-hardness wear-proof welding electrode without preheating

The present invention relates to a kind of high-hardness wear-proof welding electrode.

One of wear resisting surfacing deposited electrode subject matter is exactly that the high rigidity crack resistance good with it of deposited metal is not easy to take into account, and particularly HRC is very poor greater than 60 deposited metal general crack resistance under preheating condition not.

The XHD-6170 electric welding rod for built-up welding of Switzerland's Castolin international corporation for example, the normal temperature hardness of the deposited metal on the test specimen is HRC63-67 in the weldment test fixture when preheating condition not, crack 6, Ri Ben INGDLAROD-1000 electric welding rod for built-up welding and for example, the normal temperature hardness of deposited metal is HRC60-63 under above-mentioned similarity condition, also cracks 6.

Purpose of the present invention is exactly to propose the wear-resisting welding rod of not preheating of a kind of high rigidity, and this welding rod has higher hardness (HRC67～70) and has good crack resistance simultaneously again.

The chemical analysis of the deposited metal of welding rod of the present invention is (weight %):

Carbon 1～2%, silicon 1～2%, vanadium 4～8%, boron 0.2～1.5%, manganese 0.5～1%, chromium 2～5%, titanium 0.2～0.5%, molybdenum 7～10%, niobium 0.5～1.5%, phosphorus≤0.029%, sulphur≤0.043%, all the other are iron.

The percentage (weight %) of this chemical coating of welding electrode prescription is:

Silver strip graphite 4～8%, high carbon ferro-chrome 4～8%, molybdenum-iron 30～40%, vanadium iron 20～30%, ferro-boron 20～30%, ferrotianium 2～6%, mid-carbon fe-mn 2～6%, niobium carbide 2～6%.

Result of the test shows that this wear-proof welding electrode has higher hardness (HRC＞67) and has good crack resistance simultaneously.

The material of test piece of hardness test is A ₃Steel, test plate (panel) is of a size of 80 * 50 * 18mm, and in the longitudinal midline built-up welding, hardness is beaten in the polishing back on the HR-150 Rockwell apparatus.The electric welding machine model is ZXG7-300, straight polarity direct current (test plate (panel) connects positive pole), and welding current is 180A, and room temperature is 22 ℃, and built-up welding is three layers altogether, and cool to room temperature is measured hardness behind one welding bead of every built-up welding, and the hardness measurement result is as shown in table 1.

The hardness measurement result of table 1 wear-proof welding electrode deposited metal of the present invention

Built-up welding number of plies hardness number (HRC)

One 68 68 68.5 67 69

2 67.5 69 68 68.5 69

3 67 68 68 70 68.5

In order to illustrate that wear-proof welding electrode of the present invention has good crack resistance to do following crack resistance contrast test: material of test piece is A ₃Steel plate, be of a size of 240 * 200 * 18mm, test plate (panel) clips in advance as Fig. 1 (a), 1(b) on the weldment crazing-resistance test anchor clamps shown in, and make it that certain reversible deformation is arranged in advance, test plate (panel) produces distortion in the time of can avoiding built-up welding like this, adopts ZXG7-300 type welding machine, straight polarity direct current, with the welding current is that 180A is at test plate (panel) longitudinal center built-up welding single pass welding (welding rod of built-up welding), not preheating during built-up welding, the situation of measuring normal temperature hardness and observing crackle, the cracking test result is as shown in table 2:

Can clearly find out by table 2, compare with external similar wear resisting surfacing deposited electrode from wear-proof welding electrode of the present invention, though these external welding rod hardness numbers are a little less than welding rod of the present invention, the crack resistance of welding rod of the present invention significantly is better than above-mentioned welding rod.

Wear-proof welding electrode of the present invention keeps good crack resistance main cause under high rigidity may be the solution strengthening that made full use of multiple alloy element, intercrystalline strengthening etc., also has even tissue, and favourable carbide shape and distribution etc.

The metallograph of welding rod deposited metal of the present invention (amplifying 200 times) as shown in Figure 2, and is even by the Tissue distribution of the visible deposited metal of metallograph, crystal grain is tiny, carbide seldom is pointed shape.(table 2 is seen the literary composition back)

Embodiment:

Adopt following concrete coating proportioning (weight %):

Silver strip graphite 5%, high carbon ferro-chrome 4%, molybdenum-iron 35%, vanadium iron 26%, ferro-boron 24%, ferrotianium 2%, mid-carbon fe-mn 2%, niobium carbide 2%.

Above-mentioned batching is all sieved through 40 orders and is put into washbasin, abundant dried stirring, slowly pour Bo Meidu again into and be 48 sodium silicate, fully wet stirring, humidity are determined by experience, with 25 tons of extrusion press compactings, core wire is the H08A of diameter phi 4, the external diameter mould is φ 6.4mm, and the welding rod that suppresses just can use 350 ℃ of insulations through common low temperature and hyperthermia drying in 1.5 hours.

This welding rod is built more than ten unit test welds such as company's installing engineering place, Zhuzhou Automobile Manufacture Factory and is reflected that all this welding rod has good crack resistance through Xiangtan Iron and Steel, Xiang Tan coal mine machinery factory, Tianjin Iron Plant, China YouSe three.

The front view of Fig. 1 (a) weldment crazing-resistance test anchor clamps;

The vertical view of Fig. 1 (b) weldment crazing-resistance test anchor clamps;

Wherein 1 is test piece for welding, and 2 are the test welding bead, and 3 is anchor clamps.

The metallograph of the deposited metal of Fig. 2 wear-proof welding electrode of the present invention (* 200 times)

The crazing-resistance test result of table 2 welding rod built-up welding

Built-up welding crackle hardness

Numbering welding rod country origin and the trade mark welding rod unit of providing remarks

Situation (HRC)

The international hardness number of Switzerland's Castolin derives from

1 splits 6 63～67 Chinese agricultural machinery research institutes

Company (XHD-6710) data

The international hardness number of Switzerland's Castolin derives from

2 split 9 68～72 Chinese agricultural machinery research institutes

Company (N112) data

A kind of luxembourg patents 58,60,63

3 split 8 Wuhan Iron and Steel Company's measured hardness values

Welding rod (A45) 61

(INGDIAROD 61,63,60 Beijing are smart special wear-resisting in Japan

4 split 6 measured hardness values

-100) 62 material factories

68、70、67.5

5 welding rods of the present invention do not split 68,67 measured hardness values

Average 68.1

Claims (2)

1, a kind of high-hardness wear-proof welding electrode without preheating is characterized in that the chemical analysis percentage (weight %) of the deposited metal of this welding rod is:

Carbon 1～2%, silicon 1～2%, vanadium 4～8%, boron 0.2～1.5%, chromium 2～5%, titanium 0.2～0.5%, molybdenum 7～10%, niobium 0.5～1.5%, manganese 0.5～1%, phosphorus≤0.029%, sulphur≤0.043%, all the other are iron.

2, welding rod according to claim 1 is characterized in that the percentage (weight %) of this chemical coating of welding electrode prescription is:

Silver strip graphite 4～8%, high carbon ferro-chrome 4～8%, molybdenum-iron 30～40%, vanadium iron 20～30%, ferro-boron 20～30%, ferrotianium 2～6%, mid-carbon fe-mn 2～6%, niobium carbide 2～6%.

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