Q690高强钢中厚板全熔透焊接工艺分析

针对新材料Q690低合金高强钢中厚板普遍存在的焊接冷热裂纹及淬硬倾向大、焊后残余应力高、氢致裂纹敏感性强的问题，通过研究MK·GHS70焊丝与Q690高强钢匹配性问题，包括进行焊前处理、控制预热温度及层间温度、减小焊接热输入及正确的焊后热处理形式，得出合理的焊接参数，并通过超声探伤及力学性能检验该工艺可行性。结果表明，Q690高强钢中厚板全熔透焊接工艺完全满足设计要求和生产需要，成功解决了中厚板全熔透焊接难题。此方法已经成功用在海洋平台吊机、海洋井架等设备，取得了良好效果。

Analysis on Full Penetration Welding Process of Q690 High Strength Steel Plate with Moderate Thickness

Aiming at some characteristics of new material grade Q690 moderate thickness steel plate with high strength and low alloy, such as cold and hot welding crack, big hardening tendency, high residual stress after welding, and strong hydrogen induced cracking sensitivity. By researching on MK·GHS70 welding wire matching with high strength Q690 steel, including pre-welding treatment, controlling preheating temperature and interlayer temperature, reducing welding heat input and the right heat treatment after welding, to obtain reasonable welding parameters, and through ultrasonic flaw detection and mechanical performance inspection process feasibility. The results showed the full penetration welding process of high strength Q690 steel plate completely meet the requirements of design and production. It successfully solved the full penetration welding problem for steel plate moderate thickness. This method has been successfully adopted in offshore platform crane, marine derrick and other equipment, and achieved good results.