On 2018-08-08 14:48:54
What points should be paid attention to when welding heat-resistant steel
What points should be paid attention to when welding heat-resistant steel castings? Today, let heat resistant steel casting to give you a detailed talk about this problem!
Main point 1: The welding position of heat-resistant steel casting should choose welding, symmetry welding, then the overall welding method, in order to prevent the stress of the casting split, welding a layer (inner lapping), if the joint is small, can choose 3.2 welding wire. Welding wire 4.0 can be used for the second layer of electric welding. As the casting is very large, 1/6 turn can be used for piecewise welding.
Main point 2: For the crack of heat-resistant steel casting in electric welding, the weld should be cut along both sides of the crack first, and the deep and long of the weld should be removed and then welded again. Electric welding crack should be the first stainless steel head, from the crack root just started along the crack welding. For the strength of more than HRC38, cover to choose AI02 wire.
Point 3: For the layered welding part, the welding skin should be cleaned after the temperature of the first layer is cooled to 200-300℃, and then the second layer is welded, and so on.
Main point four: laser cutting and welding opening can be carried out with oxyacetyl block flame according to the working condition on the spot, so as to ensure the welding quality of electric welding. The surface layer of casting parts should be eliminated and cleaned to prevent defects such as oil stains and welding nodules.
Basic methods to solve the problem of heat-resistant steel casting:
Description of phenomena -- analysis of causes -- formulation of measures -- verification of effects -- further improvement
That is to engage in heat-resistant steel forging, it is necessary to put forward countermeasures from the root cause of air vent. Because you are in the scene, the idea that everybody gives is also about, cannot analyze the situation on the spot deeply for you, want to rely on oneself colleague to analyze well to be able to solve difficulty truly.
A few points for reference:
1. How dry is the core sand? Are there any organic impurities mixed in?
2. Does casting ladle overpack so that more air is brought in? Can I change the small bags for pouring?
3. How about the aeration of the casting mold and sand core?
4. Whether there are design defects in gating system design