摘要:
Provided are: an arc welding method that suppresses occurrences of blow holes in initial parts and final parts in a Zn plated steel sheet and reduces the occupancy ratio for blow holes in the welded part as a whole; and a welded joint. An arc welding method for a Zn plated steel sheet sets the gap between plates to 0.2 - 1.5 mm and includes a first step for moving a welding means from a welding initiation point at a first welding speed and performing welding by applying a first welding heat input, a second step following the first step for moving the welding means at a second welding speed and performing welding by applying a second welding heat input, and a third step following the second step for stopping the movement of the welding means and performing welding for 0.1 - 2 seconds at that stopped position. The first step includes welding performed on a welding unit under conditions wherein the first welding speed is less than the second welding speed and the first welding input heat exceeds the second welding input heat. In the third step, welding is performed at a welding current and a welding voltage lower than those in the second step.
摘要:
[Problem] To provide excellent liquid metal embrittlement cracking resistance to an arc-welded structural member using a Zn-Al-Mg based alloy coated steel plate member without restriction of the species of steel for a base steel for coating and without much increase in cost. [Solution to Problem] In a method for producing an arc-welded structural member containing a step of joining steel members by gas-shielded arc-welding to manufacture a welded structural member, at least one of the members to be joined is a hot dip Zn-Al-Mg based alloy coated steel plate member, and a shielding gas is a gas that is based on an Ar gas, a He gas or an Ar-He mixed gas and has a CO 2 concentration C CO2 (% by volume) satisfying the following expression (2) in relation to a welding heat input Q (J/cm):
摘要:
Provided is a laser welding method of materials having different thicknesses that can achieve excellent weld strength regardless of the thickness of a thick plate, and a welded member having different thicknesses. That is, the present invention is characterized by a laser welding method of materials having different thicknesses, including: abutting two plates (10), (12) having different thicknesses such that one surface of the plate (10) and one surface the plate (12) are made flush with each other; and thereafter welding the plates (10), (12) by applying a laser beam (14) to abutting surfaces thereof, wherein the laser beam (14) is made incident obliquely from the flush surface of the thin plate (10) toward an abutting end face (12a) of the thick plate (12), a target position (P) of the laser beam (14) is set on the abutting end face (12a) of the thick plate (12), and a target position depth D in the plate from a surface thereof on the incident side of the laser beam (14) is set within a range of the following expression (1), t/3 ≤ D ≤ t ...(1) (where t is a thickness, in a planar direction, of an abutting end face (10a) of the thin plate (10), and D and t are both given in mm).
摘要:
[Problem] To provide a steel sheet hot-dip-plated with a Zn-Al-Mg-based alloy coating, which is remarkably improved in point of all the burring workability, the liquid metal embrittlement cracking resistance and the corrosion resistance in the welded part thereof, as a steel material favorable for arc-welded structural members. [Means for Resolution] A plated steel sheet having a Zn-Al-Mg-based alloy coating layer formed by hot-dipping on the surface of a base steel sheet for welded structural members, wherein the base steel sheet has a specific chemical composition and has a metallographic structure of such that Ti-containing precipitates having a mean particle diameter of at most 20 nm are dispersed in the matrix formed of a ferrite phase therein, and wherein the liquid metal embrittlement cracking sensitivity index H3 value of the base steel sheet represented by the following formula (3) and indicating the relationship between the contents of the steel components and the thickness t (mm) of the steel sheet is at most 2.90:
摘要:
[Problem] To provide a steel sheet hot-dip-plated with a Zn-Al-Mg-based alloy coating, which is remarkably improved in point of all the burring workability, the liquid metal embrittlement cracking resistance and the corrosion resistance in the welded part thereof, as a steel material favorable for arc-welded structural members. [Means for Resolution] A plated steel sheet having a Zn-Al-Mg-based alloy coating layer formed by hot-dipping on the surface of a base steel sheet for welded structural members, wherein the base steel sheet has a specific chemical composition and has a metallographic structure of such that Ti-containing precipitates having a mean particle diameter of at most 20 nm are dispersed in the matrix formed of a ferrite phase therein, and wherein the liquid metal embrittlement cracking sensitivity index H3 value of the base steel sheet represented by the following formula (3) and indicating the relationship between the contents of the steel components and the thickness t (mm) of the steel sheet is at most 2.90: H 3 Value = C / 0.2 + Si / 5.0 + Mn / 1.3 + Cr / 1.0 + Mo / 1.2 + 0.4 t − 0.7 Cr + Mo 1 / 2
摘要:
Provided is a laser welding method of materials having different thicknesses that can achieve excellent weld strength regardless of the thickness of a thick plate, and a welded member having different thicknesses. That is, the present invention is characterized by a laser welding method of materials having different thicknesses, including: abutting two plates (10), (12) having different thicknesses such that one surface of the plate (10) and one surface the plate (12) are made flush with each other; and thereafter welding the plates (10), (12) by applying a laser beam (14) to abutting surfaces thereof, wherein the laser beam (14) is made incident obliquely from the flush surface of the thin plate (10) toward an abutting end face (12a) of the thick plate (12), a target position (P) of the laser beam (14) is set on the abutting end face (12a) of the thick plate (12), and a target position depth D in the plate from a surface thereof on the incident side of the laser beam (14) is set within a range of the following expression (1), t/3 ‰¤ D ‰¤ t ...(1) (where t is a thickness, in a planar direction, of an abutting end face (10a) of the thin plate (10), and D and t are both given in mm).
摘要:
Hot dip Zn-based alloy coated steel sheets are arc-weld in such a way that (a) a current waveform is a pulsed current waveform in which (i) a peak current and a base current alternate with each other at a pulse period of 1 ms to 50 ms and (ii) an average welding current is 100 A to 350 A and (b) an average welding voltage is 20 V to 35 V. Each of the hot dip Zn-based alloy coated steel sheets includes a coating layer that contains Zn as a main component and that contains Al at a concentration of 1.0% by mass to 22.0% by mass, and has a coating weight W of 15 g/m 2 to 250 g/m 2 [ Fig. 1 ]
摘要翻译:(a)电流波形是脉冲电流波形,其中(i)峰值电流和基极电流在脉冲周期彼此交替 (ii)平均焊接电流为100A至350A,和(b)平均焊接电压为20V至35V。每个热浸Zn基合金涂层钢板包括涂层 其含有Zn作为主要成分,并且含有浓度为1.0质量%至22.0质量%的Al,并具有15g / m 2至250g / m 2的涂层重量W。 1]