CN102000922A - Cast iron welding technique using cold welding and bead welding - Google Patents

Abstract

The invention disclose a cast iron welding process using cold welding and bead welding, comprising the following welding process steps of: (1) clearing parts to be welded: removing oil stains, iron rust and other flaws; (2) preparing a welding rod: using an E5015 basic welding rod of which the diameter is 3.2mm, drying the welding rod at a temperature from 360 DEG C to 380 DEG C for 1 to 2 hours, putting the dried welding rod in a thermal insulation bucket, and preserving heat for later use; (3) welding: selecting a direct current welding machine, and adopting a direct current straight polarity method, namely that the welding rod is connected with a negative electrode, a component to be welded is connected with a positive electrode, and the current is kept in a range from 95A to 105A. In the invention, a casting is welded by adopting the casting welding process using a cold welding method. The welding process using cold welding and bead welding solves the problems that the work environments of a casting welding process using a hot welding method are poor, and the site heating conditions can not meet the requirements on the welding process using a hot welding method in most conditions. Welding time is shortened, and welding materials are saved.

Description

Cold welding of cast iron built-up welding welding procedure

Affiliated technical field

The invention belongs to solder technology, particularly relate to the welding procedure of foundry goods being carried out the cold welding built-up welding.

Background technology

Foundry goods is welded with hot weld and two kinds of methods of cold welding.The hot weld method is to begin welding with foundry goods integral body or after being heated to 600～700 ℃ on a large scale, and workpiece temperature is not less than 400 ℃ in the welding process, and postwelding is heated to 600～700 ℃ at once and carries out the stress relief annealing processing.The cold welding method is the method for foundry goods being carried out REPAIR WELDING when bulk temperature is not higher than 200 ℃..Because hot weld method working environment is relatively poor, and heating-up temperature is difficult to reach requirement under the condition at many scenes.And prior art is carried out the method that cold welding is repaired to foundry goods, exists welding effect bad mostly, the cost problem of higher.

Summary of the invention

The object of the invention provides a kind of foundry goods cold welding built-up welding welding procedure, and foundry goods is directly welded, and when reducing the Welder, saves welding material.

Technical scheme of the present invention is: cold welding of cast iron built-up welding welding procedure, adopt following welding procedure step:

(1) clears up position to be welded: eliminate defect factors such as greasy dirt, iron rust;

(2) prepare welding rod: with the E5015 basic electrode of diameter 3.2 mm, welding rod is dried 1～2h under 360～380 ℃ temperature, put into the heat-preserving container heat preservation for standby use after the oven dry;

(3) welding: select dc welding machine for use, adopting the straight polarity direct current method is that welding rod connects the mode that negative electrode, weldment connect anode, and current range remains on 95～105A.

Progressive effect of the present invention: adopt foundry goods cold welding method welding procedure that foundry goods is welded, solved because the working environment of foundry goods hot weld method welding procedure is relatively poor, simultaneously heating-up temperature is difficult to reach the problem of the requirement of hot weld method welding procedure under the condition at many scenes, when having reduced the Welder, saved welding material.

The specific embodiment

Embodiment: the wearing and tearing of roughing main gear reducer cast-iron chock are repaired.

Certain high line factory carries out year-end maintenance, and one of them key project is exactly the processing of roughing main gear reducer cast-iron chock wearing and tearing.Because cast-iron chock is worn and torn by long-duration load, cacophonia during work, spot check person can enter reductor inside from reductor top window, reaches 0.8mm with round gap with bearing in the clearance gauge measurement driving gear output bore hole.High line factory owner reductor is the old equipment that reuses, and the grey cast-iron bearing block is worked under the environment of high temperature and stress for a long time, produces wearing and tearing.This foundry goods weighs four or five tons, is worth 400,000 yuan, does not have spare part in the storehouse.Adopt the soldering of hot weld method in the past, because of cast iron takes place rottenly, and oil-bearing layer is arranged, the graphite amount of separating out increases, and assembles factor such as grow up, and defectives such as lack of fusion, pore, crackle have appearred in the cast iron overlay cladding.Because welding casting pig easily forms cold crack, weld metal and fusion area are peeled off, particularly thick workpiece, and the crackle tendency is big.Solve above difficult point, must formulate the welding procedure that adapts to, guarantee to be welded into power.The present invention has adopted following method of operating:

(1) clear up position to be welded: we toast welding portion slightly on a large scale with oxy arc, remove the greasy dirt of surface to be welded, and play casting the scaling loss effect of loose hole and oil-containing interlayer greasy dirt, reduce the pore source as far as possible.

(2) prepare welding rod: with the E5015 basic electrode of diameter 3.2 mm, welding rod is dried 2h under 360 ℃ temperature, put into the heat-preserving container heat preservation for standby use after the oven dry.

(3) welding: select dc welding machine for use, adopting the straight polarity direct current method is that welding rod connects the mode that negative electrode, weldment connect anode, and current range remains on 100 A.

Because built-up welding is the medial surface at a circular arc, so in the welding process, adopt the segmentation weldering, arc surface is divided into ten five equilibriums, the staggered welding in middle both sides, the arc manipulation linear pattern is not swung more can not adopt and is drawn the circle arc manipulation, and adopts along arc-welding.

Use the hand hammer of apicule head (top is R=3～5mm fillet) on welding bead, to pound hammering immediately after having welded for every section, hammering wants appropriateness evenly, it is fast that speed is wanted, strength is by heavy gradually light, welding bead surface after the hammering is covered with thickly dotted pitting, the hammering time is in 15 s, because crackle generally occurs in about postwelding 10 s. and hammering can alleviate the shrinkage stress of welding bead, strengthens toughness.

Interlayer temperature is strict controlled in below 60 ℃, and postwelding takes slow cooling to reduce cooling velocity, avoids forming the spoken parts in traditional operas phenomenon, reduces welding stress.

By above implementation of processes, solved the lack of fusion that occurs fully and the problem that is difficult for burn-oning when repair welding cast iron, wearability is stronger than import welding rod, the built-up welding of current base and loam cake, the cost of welding rod E5015 is 1% of a Foreign Iron welding rod, 3% price of domestic electrode for cast iron.This time the nearly 20 kilograms of welding rods of built-up welding are finished the reparation task of this foundry goods with guaranteeing quality, and save nearly 20,000 yuan of welding rod cost value.

Claims (1)

1. cold welding of cast iron built-up welding welding procedure, adopt following welding procedure step:

(1) clears up position to be welded: eliminate defect factors such as greasy dirt, iron rust;

(2) prepare welding rod: with the E5015 basic electrode of diameter 3.2 mm, welding rod is dried 1～2h under 360～380 ℃ temperature, put into the heat-preserving container heat preservation for standby use after the oven dry;

(3) welding: select dc welding machine for use, adopting the straight polarity direct current method is that welding rod connects the mode that negative electrode, weldment connect anode, and current range remains on 95～105 A.