During welding, wire consumables can essentially contribute to the resulting microstructures and mechanical properties. In order to maintain high toughness even for high strength steel, certain microstructures are desirable, particularly acicular ferrite. An efficient, controllable test method was developed during which the wire is molten and experiences a thermal cycle by a shaped laser pulse, or a sequence of pulses, which shall resemble continuous laser-arc hybrid welding or narrow gap multi-layer laser welding. Different thermal cycles and wire chemistries have led to manifold microstructures. The morphology of the microstructures can become complex. Therefore, more detailed characterization of essential morphology aspects was carried out, to distinguish different results. The thermal cycles from quenching have led to shorter, thicker laths with more random orientation. The latter can be favourable for high toughness. Short reheating cycles by about 200 K/s caused finer, longer and more parallel laths, as for bainite, in varying size of blocks. Other aspects considered were grain boundary ferrite and non-metallic inclusions. Systematic variation of the thermal cycle by the testing method along with systematic description of microstructure morphology in more detail is a promising method to identify and optimize favoured routes for wire chemistry and welding techniques.