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不!对于合金成分稍高的高强度钢来说,由于它的强度和韧性需要调质(淬火加高温回火)才能得到,所以焊接后的冷却速度决不是越低越好。通常,在焊接低合金钢时,从防止裂纹的角度出发,往往倾向于较低的冷却速度,特别是在可能发生氢裂的情况下。我们知道,假设扩散氢的量一定,那么在700～300℃或是800～500℃的范围内冷却时间越长(即冷却速度越低),致裂所需的应力就越大,就是抗裂强度越高。这就是通常所说的概念,即降低冷却速度可以提高抗裂强度。可是,对调质钢来说,降低冷却速度并不能使影响区得到最好的冲击韧
No. For high-strength steels with a slightly higher alloy composition, the cooling rate after soldering is by no means as low as possible due to the fact that its strength and toughness require tempering (quenching and tempering). In general, when welding low-alloy steels, there is often a tendency toward lower cooling rates from the standpoint of crack prevention, especially where a hydrogen crack may occur. We know that assuming that the amount of diffused hydrogen is constant, the longer the cooling time (ie, the lower the cooling rate) in the range of 700 to 300 ° C or 800 to 500 ° C, the greater the stress required for cracking is cracking The higher the intensity. This is what is commonly known as the concept that lowering the cooling rate increases the crack resistance. However, the quenched and tempered steel, reducing the cooling rate does not affect the area to get the best impact toughness