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前言 GB794加强半圆头方颈螺栓,是纺织机械用的主要紧固件。目前国内生产的织机螺栓,主要是用A3、20和ML15等低碳钢,经热压或冷镦成形后搓丝、退火等工序制成,其抗拉强度在40～60kgf/mm~2。织机运转中,螺栓承受反复冲击及横向、轴向等交变复杂的动载荷,因此对其强韧性、耐疲劳性等要求较高。尤其是打棒和筘框托脚两个部位的螺栓,受力状态和工作条件更苛刻,易发生过载拉断和疲劳断裂,螺栓使用寿命低。普通GB794螺栓强度已不适应织机运转的需要,特别是宽幅织机对螺
Preface GB794 strengthen the head of the square head bolt, is the main fastener used in textile machinery. At present, the domestic production of loom bolts, mainly with A320 and ML15 and other low-carbon steel, hot or cold heading after forming wire rolling, annealing and other processes made of its tensile strength 40 ~ 60kgf / mm ~ 2 . Loom operation, the bolt withstand repeated impact and horizontal, axial and other alternating dynamic load complex, so its toughness, fatigue resistance and other requirements. In particular, playing sticks and reed frame supporting the two parts of the bolt, the stress state and working conditions are more demanding, prone to overload rupture and fatigue fracture, bolt life is low. Ordinary GB794 bolt strength has not adapted to the needs of loom operation, in particular, a wide loom on the screw